47 files changed, 846 insertions, 325 deletions
diff --git a/src/burn/burn.sln b/src/burn/burn.sln
deleted file mode 100644
index c820a467..00000000
--- a/src/burn/burn.sln
+++ /dev/null
@@ -1,63 +0,0 @@
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 17
-VisualStudioVersion = 17.0.32014.148
-MinimumVisualStudioVersion = 15.0.26124.0
-Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "engine", "engine\engine.vcxproj", "{8119537D-E1D9-6591-D51A-49768A2F9C37}"
-EndProject
-Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "stub", "stub\stub.vcxproj", "{C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}"
-EndProject
-Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "BurnUnitTest", "test\BurnUnitTest\BurnUnitTest.vcxproj", "{9D1F1BA3-9393-4833-87A3-D5F1FC08EF67}"
-EndProject
-Global
-        GlobalSection(SolutionConfigurationPlatforms) = preSolution
-                Debug|ARM64 = Debug|ARM64
-                Debug|x64 = Debug|x64
-                Debug|x86 = Debug|x86
-                Release|ARM64 = Release|ARM64
-                Release|x64 = Release|x64
-                Release|x86 = Release|x86
-        EndGlobalSection
-        GlobalSection(ProjectConfigurationPlatforms) = postSolution
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Debug|ARM64.ActiveCfg = Debug|ARM64
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Debug|ARM64.Build.0 = Debug|ARM64
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Debug|x64.ActiveCfg = Debug|x64
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Debug|x64.Build.0 = Debug|x64
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Debug|x86.ActiveCfg = Debug|Win32
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Debug|x86.Build.0 = Debug|Win32
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Release|ARM64.ActiveCfg = Release|ARM64
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Release|ARM64.Build.0 = Release|ARM64
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Release|x64.ActiveCfg = Release|x64
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Release|x64.Build.0 = Release|x64
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Release|x86.ActiveCfg = Release|Win32
-                {8119537D-E1D9-6591-D51A-49768A2F9C37}.Release|x86.Build.0 = Release|Win32
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Debug|ARM64.ActiveCfg = Debug|ARM64
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Debug|ARM64.Build.0 = Debug|ARM64
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Debug|x64.ActiveCfg = Debug|x64
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Debug|x64.Build.0 = Debug|x64
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Debug|x86.ActiveCfg = Debug|Win32
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Debug|x86.Build.0 = Debug|Win32
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Release|ARM64.ActiveCfg = Release|ARM64
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Release|ARM64.Build.0 = Release|ARM64
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Release|x64.ActiveCfg = Release|x64
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Release|x64.Build.0 = Release|x64
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Release|x86.ActiveCfg = Release|Win32
-                {C38373AA-882F-4F55-B03F-2AAB4BFBE3F1}.Release|x86.Build.0 = Release|Win32
-                {9D1F1BA3-9393-4833-87A3-D5F1FC08EF67}.Debug|ARM64.ActiveCfg = Debug|x64
-                {9D1F1BA3-9393-4833-87A3-D5F1FC08EF67}.Debug|x64.ActiveCfg = Debug|x64
-                {9D1F1BA3-9393-4833-87A3-D5F1FC08EF67}.Debug|x64.Build.0 = Debug|x64
-                {9D1F1BA3-9393-4833-87A3-D5F1FC08EF67}.Debug|x86.ActiveCfg = Debug|Win32
-                {9D1F1BA3-9393-4833-87A3-D5F1FC08EF67}.Debug|x86.Build.0 = Debug|Win32
-                {9D1F1BA3-9393-4833-87A3-D5F1FC08EF67}.Release|ARM64.ActiveCfg = Release|x64
-                {9D1F1BA3-9393-4833-87A3-D5F1FC08EF67}.Release|x64.ActiveCfg = Release|x64
-                {9D1F1BA3-9393-4833-87A3-D5F1FC08EF67}.Release|x64.Build.0 = Release|x64
-                {9D1F1BA3-9393-4833-87A3-D5F1FC08EF67}.Release|x86.ActiveCfg = Release|Win32
-                {9D1F1BA3-9393-4833-87A3-D5F1FC08EF67}.Release|x86.Build.0 = Release|Win32
-        EndGlobalSection
-        GlobalSection(SolutionProperties) = preSolution
-                HideSolutionNode = FALSE
-        EndGlobalSection
-        GlobalSection(ExtensibilityGlobals) = postSolution
-                SolutionGuid = {A35910C5-8A89-473E-9578-E084172DD3C9}
-        EndGlobalSection
-EndGlobal
diff --git a/src/burn/burn.slnx b/src/burn/burn.slnx
new file mode 100644
index 00000000..76a93036
--- /dev/null
+++ b/src/burn/burn.slnx
@@ -0,0 +1,13 @@
+<Solution>
+  <Configurations>
+    <Platform Name="ARM64" />
+    <Platform Name="x64" />
+    <Platform Name="x86" />
+  </Configurations>
+  <Project Path="engine/engine.vcxproj" Id="8119537d-e1d9-6591-d51a-49768a2f9c37" />
+  <Project Path="stub/stub.vcxproj" Id="c38373aa-882f-4f55-b03f-2aab4bfbe3f1" />
+  <Project Path="test/BurnUnitTest/BurnUnitTest.vcxproj" Id="9d1f1ba3-9393-4833-87a3-d5f1fc08ef67">
+    <Platform Solution="*|ARM64" Project="x64" />
+    <Build Solution="*|ARM64" Project="false" />
+  </Project>
+</Solution>
diff --git a/src/burn/engine/approvedexe.cpp b/src/burn/engine/approvedexe.cpp
index 28b26d6d..27ec2adc 100644
--- a/src/burn/engine/approvedexe.cpp
+++ b/src/burn/engine/approvedexe.cpp
@@ -3,6 +3,13 @@
 #include "precomp.h"
+// internal function declarations
+static HRESULT IsRunDll32(
+    __in BURN_VARIABLES* pVariables,
+    __in LPCWSTR wzExecutablePath
+    );
 // function definitions
 extern "C" HRESULT ApprovedExesParseFromXml(
@@ -122,7 +129,7 @@ extern "C" HRESULT ApprovedExesFindById(
    {
        pApprovedExe = &pApprovedExes->rgApprovedExes[i];
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, pApprovedExe->sczId, -1, wzId, -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(pApprovedExe->sczId, -1, wzId, -1, FALSE))
        {
            *ppApprovedExe = pApprovedExe;
            ExitFunction1(hr = S_OK);
@@ -221,12 +228,15 @@ LExit:
 extern "C" HRESULT ApprovedExesVerifySecureLocation(
    __in BURN_CACHE* pCache,
    __in BURN_VARIABLES* pVariables,
-    __in LPCWSTR wzExecutablePath
+    __in LPCWSTR wzExecutablePath,
+    __in int argc,
+    __in LPCWSTR* argv
    )
 {
    HRESULT hr = S_OK;
    LPWSTR scz = NULL;
    LPWSTR sczSecondary = NULL;
+    LPWSTR sczRunDll32Param = NULL;
    const LPCWSTR vrgSecureFolderVariables[] = {
        L"ProgramFiles64Folder",
@@ -273,11 +283,104 @@ extern "C" HRESULT ApprovedExesVerifySecureLocation(
        ExitFunction();
    }
+    // Test if executable is rundll32.exe, and it's target is in a secure location
+    // Example for CUDA UninstallString: "C:\WINDOWS\SysWOW64\RunDll32.EXE" "C:\Program Files\NVIDIA Corporation\Installer2\InstallerCore\NVI2.DLL",UninstallPackage CUDAToolkit_12.8
+    if (argc && argv && argv[0] && *argv[0])
+    {
+        hr = IsRunDll32(pVariables, wzExecutablePath);
+        ExitOnFailure(hr, "Failed to test whether executable is rundll32");
+        if (hr == S_OK)
+        {
+            LPCWSTR szComma = wcschr(argv[0], L',');
+            if (szComma && *szComma)
+            {
+                hr = StrAllocString(&sczRunDll32Param, argv[0], szComma - argv[0]);
+                ExitOnFailure(hr, "Failed to allocate string");
+            }
+            else
+            {
+                hr = StrAllocString(&sczRunDll32Param, argv[0], 0);
+                ExitOnFailure(hr, "Failed to allocate string");
+            }
+            hr = ApprovedExesVerifySecureLocation(pCache, pVariables, sczRunDll32Param, 0, NULL);
+            ExitOnFailure(hr, "Failed to test whether rundll32's parameter, '%ls', is in a secure location", sczRunDll32Param);
+            if (hr == S_OK)
+            {
+                ExitFunction();
+            }
+        }
+    }
    hr = S_FALSE;
 LExit:
    ReleaseStr(scz);
    ReleaseStr(sczSecondary);
+    ReleaseStr(sczRunDll32Param);
+    return hr;
+}
+static HRESULT IsRunDll32(
+    __in BURN_VARIABLES* pVariables,
+    __in LPCWSTR wzExecutablePath
+    )
+{
+    HRESULT hr = S_OK;
+    LPWSTR sczFolder = NULL;
+    LPWSTR sczFullPath = NULL;
+    BOOL fEqual = FALSE;
+    hr = VariableGetString(pVariables, L"SystemFolder", &sczFolder);
+    ExitOnFailure(hr, "Failed to get the variable: SystemFolder");
+    hr = PathConcat(sczFolder, L"rundll32.exe", &sczFullPath);
+    ExitOnFailure(hr, "Failed to combine paths");
+    hr = PathCompareCanonicalized(wzExecutablePath, sczFullPath, &fEqual);
+    ExitOnFailure(hr, "Failed to compare paths");
+    if (fEqual)
+    {
+        hr = S_OK;
+        ExitFunction();
+    }
+    hr = VariableGetString(pVariables, L"System64Folder", &sczFolder);
+    ExitOnFailure(hr, "Failed to get the variable: System64Folder");
+    hr = PathConcat(sczFolder, L"rundll32.exe", &sczFullPath);
+    ExitOnFailure(hr, "Failed to combine paths");
+    hr = PathCompareCanonicalized(wzExecutablePath, sczFullPath, &fEqual);
+    ExitOnFailure(hr, "Failed to compare paths");
+    if (fEqual)
+    {
+        hr = S_OK;
+        ExitFunction();
+    }
+    // Sysnative
+    hr = PathSystemWindowsSubdirectory(L"SysNative\\", &sczFolder);
+    ExitOnFailure(hr, "Failed to append SysNative directory.");
+    hr = PathConcat(sczFolder, L"rundll32.exe", &sczFullPath);
+    ExitOnFailure(hr, "Failed to combine paths");
+    hr = PathCompareCanonicalized(wzExecutablePath, sczFullPath, &fEqual);
+    ExitOnFailure(hr, "Failed to compare paths");
+    if (fEqual)
+    {
+        hr = S_OK;
+        ExitFunction();
+    }
+    hr = S_FALSE;
+LExit:
+    ReleaseStr(sczFolder);
+    ReleaseStr(sczFullPath);
    return hr;
 }
diff --git a/src/burn/engine/approvedexe.h b/src/burn/engine/approvedexe.h
index 7a68c174..0f441485 100644
--- a/src/burn/engine/approvedexe.h
+++ b/src/burn/engine/approvedexe.h
@@ -58,7 +58,9 @@ HRESULT ApprovedExesLaunch(
 HRESULT ApprovedExesVerifySecureLocation(
    __in BURN_CACHE* pCache,
    __in BURN_VARIABLES* pVariables,
-    __in LPCWSTR wzExecutablePath
+    __in LPCWSTR wzExecutablePath,
+    __in int argc,
+    __in LPCWSTR* argv
    );
diff --git a/src/burn/engine/bootstrapperapplication.cpp b/src/burn/engine/bootstrapperapplication.cpp
index dc3bd5da..346c47a5 100644
--- a/src/burn/engine/bootstrapperapplication.cpp
+++ b/src/burn/engine/bootstrapperapplication.cpp
@@ -674,7 +674,7 @@ static HRESULT VerifyPipeSecret(
    hr = StrAlloc(&sczVerificationSecret, cbVerificationSecret / sizeof(WCHAR) + 1);
    ExitOnFailure(hr, "Failed to allocate buffer for bootstrapper application verification secret.");
-    FileReadHandle(hPipe, reinterpret_cast<LPBYTE>(sczVerificationSecret), cbVerificationSecret);
+    hr = FileReadHandle(hPipe, reinterpret_cast<LPBYTE>(sczVerificationSecret), cbVerificationSecret);
    ExitOnFailure(hr, "Failed to read verification secret from bootstrapper application pipe.");
    // Verify the secrets match.
diff --git a/src/burn/engine/bundlepackageengine.cpp b/src/burn/engine/bundlepackageengine.cpp
index 612da389..7ada5f6a 100644
--- a/src/burn/engine/bundlepackageengine.cpp
+++ b/src/burn/engine/bundlepackageengine.cpp
@@ -146,7 +146,7 @@ extern "C" HRESULT BundlePackageEngineParseRelatedCodes(
        hr = XmlGetAttributeEx(pixnElement, L"Code", &sczCode);
        ExitOnFailure(hr, "Failed to get @Code.");
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, sczAction, -1, L"Detect", -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(sczAction, -1, L"Detect", -1, FALSE))
        {
            hr = MemEnsureArraySizeForNewItems(reinterpret_cast<LPVOID*>(prgsczDetectCodes), *pcDetectCodes, 1, sizeof(LPWSTR), 5);
            ExitOnFailure(hr, "Failed to resize Detect code array");
@@ -155,7 +155,7 @@ extern "C" HRESULT BundlePackageEngineParseRelatedCodes(
            sczCode = NULL;
            *pcDetectCodes += 1;
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, sczAction, -1, L"Upgrade", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(sczAction, -1, L"Upgrade", -1, FALSE))
        {
            hr = MemEnsureArraySizeForNewItems(reinterpret_cast<LPVOID*>(prgsczUpgradeCodes), *pcUpgradeCodes, 1, sizeof(LPWSTR), 5);
            ExitOnFailure(hr, "Failed to resize Upgrade code array");
@@ -164,7 +164,7 @@ extern "C" HRESULT BundlePackageEngineParseRelatedCodes(
            sczCode = NULL;
            *pcUpgradeCodes += 1;
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, sczAction, -1, L"Addon", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(sczAction, -1, L"Addon", -1, FALSE))
        {
            hr = MemEnsureArraySizeForNewItems(reinterpret_cast<LPVOID*>(prgsczAddonCodes), *pcAddonCodes, 1, sizeof(LPWSTR), 5);
            ExitOnFailure(hr, "Failed to resize Addon code array");
@@ -173,7 +173,7 @@ extern "C" HRESULT BundlePackageEngineParseRelatedCodes(
            sczCode = NULL;
            *pcAddonCodes += 1;
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, sczAction, -1, L"Patch", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(sczAction, -1, L"Patch", -1, FALSE))
        {
            hr = MemEnsureArraySizeForNewItems(reinterpret_cast<LPVOID*>(prgsczPatchCodes), *pcPatchCodes, 1, sizeof(LPWSTR), 5);
            ExitOnFailure(hr, "Failed to resize Patch code array");
@@ -686,7 +686,7 @@ static BUNDLE_QUERY_CALLBACK_RESULT CALLBACK QueryRelatedBundlesCallback(
    BOOTSTRAPPER_RELATION_TYPE relationType = RelatedBundleConvertRelationType(pBundle->relationType);
    BOOL fPerMachine = BUNDLE_INSTALL_CONTEXT_MACHINE == pBundle->installContext;
-    if (CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pBundle->wzBundleCode, -1, pPackage->Bundle.sczBundleCode, -1) &&
+    if (CSTR_EQUAL == ::CompareStringOrdinal(pBundle->wzBundleCode, -1, pPackage->Bundle.sczBundleCode, -1, TRUE) &&
        pPackage->Bundle.fWin64 == (REG_KEY_64BIT == pBundle->regBitness))
    {
        Assert(BOOTSTRAPPER_RELATION_UPGRADE == relationType);
@@ -817,7 +817,7 @@ static HRESULT ExecuteBundle(
        if (pPackage->fPerMachine)
        {
-            hr = ApprovedExesVerifySecureLocation(pCache, pVariables, sczExecutablePath);
+            hr = ApprovedExesVerifySecureLocation(pCache, pVariables, sczExecutablePath, argcArp - 1, (argcArp > 1) ? const_cast<LPCWSTR*>(argvArp + 1) : NULL);
            ExitOnFailure(hr, "Failed to verify the QuietUninstallString executable path is in a secure location: %ls", sczExecutablePath);
            if (S_FALSE == hr)
            {
@@ -940,7 +940,7 @@ static HRESULT ExecuteBundle(
    if (wzRelationTypeCommandLine)
    {
-        hr = StrAllocConcatFormatted(&sczBaseCommand, L" -%ls", wzRelationTypeCommandLine);
+        hr = StrAllocConcatFormatted(&sczBaseCommand, L" -quiet -%ls", wzRelationTypeCommandLine);
        ExitOnFailure(hr, "Failed to append relation type argument.");
    }
diff --git a/src/burn/engine/burnextension.cpp b/src/burn/engine/burnextension.cpp
index 536dbcc9..50657f32 100644
--- a/src/burn/engine/burnextension.cpp
+++ b/src/burn/engine/burnextension.cpp
@@ -214,7 +214,7 @@ EXTERN_C HRESULT BurnExtensionFindById(
    {
        pExtension = &pBurnExtensions->rgExtensions[i];
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, pExtension->sczId, -1, wzId, -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(pExtension->sczId, -1, wzId, -1, FALSE))
        {
            *ppExtension = pExtension;
            ExitFunction1(hr = S_OK);
diff --git a/src/burn/engine/burnpipe.cpp b/src/burn/engine/burnpipe.cpp
index 25d602b1..102ccb4f 100644
--- a/src/burn/engine/burnpipe.cpp
+++ b/src/burn/engine/burnpipe.cpp
@@ -446,11 +446,11 @@ extern "C" HRESULT BurnPipeChildConnect(
    // Try to connect to the parent.
    hr = PipeClientConnect(pConnection->sczName, &pConnection->hPipe);
-    ExitOnRootFailure(hr, "Failed to open parent pipe: %ls", sczPipeName)
+    ExitOnRootFailure(hr, "Failed to open parent pipe: %ls", pConnection->sczName)
    // Verify the parent and notify it that the child connected.
    hr = ChildPipeConnected(pConnection->hPipe, pConnection->sczSecret, &pConnection->dwProcessId);
-    ExitOnFailure(hr, "Failed to verify parent pipe: %ls", sczPipeName);
+    ExitOnFailure(hr, "Failed to verify parent pipe: %ls", pConnection->sczName);
    if (fCompanion)
    {
@@ -511,11 +511,11 @@ static HRESULT ChildPipeConnected(
    hr = StrAlloc(&sczVerificationSecret, cbVerificationSecret / sizeof(WCHAR) + 1);
    ExitOnFailure(hr, "Failed to allocate buffer for verification secret.");
-    FileReadHandle(hPipe, reinterpret_cast<LPBYTE>(sczVerificationSecret), cbVerificationSecret);
+    hr = FileReadHandle(hPipe, reinterpret_cast<LPBYTE>(sczVerificationSecret), cbVerificationSecret);
    ExitOnFailure(hr, "Failed to read verification secret from parent pipe.");
    // Verify the secrets match.
-    if (CSTR_EQUAL != ::CompareStringW(LOCALE_NEUTRAL, 0, sczVerificationSecret, -1, wzSecret, -1))
+    if (CSTR_EQUAL != ::CompareStringOrdinal(sczVerificationSecret, -1, wzSecret, -1, FALSE))
    {
        hr = HRESULT_FROM_WIN32(ERROR_INVALID_DATA);
        ExitOnRootFailure(hr, "Verification secret from parent does not match.");
diff --git a/src/burn/engine/cabextract.cpp b/src/burn/engine/cabextract.cpp
index 5663c3f7..2140130d 100644
--- a/src/burn/engine/cabextract.cpp
+++ b/src/burn/engine/cabextract.cpp
@@ -833,9 +833,13 @@ static UINT FAR DIAMONDAPI CabWrite(
    case BURN_CAB_OPERATION_STREAM_TO_BUFFER:
        // copy to target buffer
-        memcpy_s(pContext->Cabinet.pbTargetBuffer + pContext->Cabinet.iTargetBuffer, pContext->Cabinet.cbTargetBuffer - pContext->Cabinet.iTargetBuffer, pv, cb);
+        if (memcpy_s(pContext->Cabinet.pbTargetBuffer + pContext->Cabinet.iTargetBuffer, pContext->Cabinet.cbTargetBuffer - pContext->Cabinet.iTargetBuffer, pv, cb))
-        pContext->Cabinet.iTargetBuffer += cb;
+        {
+            hr = E_INSUFFICIENT_BUFFER;
+            ExitOnRootFailure(hr, "Failed to copy data to target buffer during cabinet extraction.");
+        }
+        pContext->Cabinet.iTargetBuffer += cb;
        cbWrite = cb;
        break;
diff --git a/src/burn/engine/cache.cpp b/src/burn/engine/cache.cpp
index 16db4a81..c85a1be4 100644
--- a/src/burn/engine/cache.cpp
+++ b/src/burn/engine/cache.cpp
@@ -260,6 +260,9 @@ extern "C" HRESULT CacheInitializeSources(
    hr = PathForCurrentProcess(&sczCurrentPath, NULL);
    ExitOnFailure(hr, "Failed to get current process path.");
+    hr = VariableSetString(pVariables, BURN_BUNDLE_SOURCE_PROCESS_PATH, sczCurrentPath, FALSE, FALSE);
+    ExitOnFailure(hr, "Failed to set %ls variable.", BURN_BUNDLE_SOURCE_PROCESS_PATH);
    // Determine if we are running from the package cache or not.
    hr = CacheGetCompletedPath(pCache, pRegistration->fPerMachine, pRegistration->sczCode, &sczCompletedFolder);
    ExitOnFailure(hr, "Failed to get completed path for bundle.");
@@ -275,6 +278,9 @@ extern "C" HRESULT CacheInitializeSources(
    hr = PathGetDirectory(sczCurrentPath, &pCache->sczSourceProcessFolder);
    ExitOnFailure(hr, "Failed to initialize cache source folder.");
+    hr = VariableSetString(pVariables, BURN_BUNDLE_SOURCE_PROCESS_FOLDER, pCache->sczSourceProcessFolder, FALSE, FALSE);
+    ExitOnFailure(hr, "Failed to set %ls variable.", BURN_BUNDLE_SOURCE_PROCESS_FOLDER);
    // If we're not running from the cache, ensure the original source is set.
    if (!pCache->fRunningFromCache)
    {
@@ -357,6 +363,8 @@ extern "C" HRESULT CacheEnsureBaseWorkingFolder(
            }
            pWorkingFolderAcl = reinterpret_cast<LPSECURITY_ATTRIBUTES>(MemAlloc(sizeof(SECURITY_ATTRIBUTES), TRUE));
+            ExitOnNull(pWorkingFolderAcl, hr, E_OUTOFMEMORY, "Failed to allocate security attributes.");
            pWorkingFolderAcl->nLength = sizeof(SECURITY_ATTRIBUTES);
            pWorkingFolderAcl->lpSecurityDescriptor = psd;
            pWorkingFolderAcl->bInheritHandle = FALSE;
@@ -613,8 +621,8 @@ extern "C" HRESULT CacheGetLocalSourcePaths(
    hr = GetLastUsedSourceFolder(pVariables, &sczLastSourceFolder);
    fPreferSourcePathLocation = !pCache->fRunningFromCache || FAILED(hr);
-    fTryLastFolder = SUCCEEDED(hr) && sczLastSourceFolder && *sczLastSourceFolder && CSTR_EQUAL != ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pCache->sczSourceProcessFolder, -1, sczLastSourceFolder, -1);
+    fTryLastFolder = SUCCEEDED(hr) && sczLastSourceFolder && *sczLastSourceFolder && CSTR_EQUAL != ::CompareStringOrdinal(pCache->sczSourceProcessFolder, -1, sczLastSourceFolder, -1, TRUE);
-    fTryRelativePath = CSTR_EQUAL != ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, wzSourcePath, -1, wzRelativePath, -1);
+    fTryRelativePath = CSTR_EQUAL != ::CompareStringOrdinal(wzSourcePath, -1, wzRelativePath, -1, TRUE);
    fSourceIsAbsolute = PathIsRooted(wzSourcePath);
    // If the source path provided is a full path, try that first.
@@ -791,7 +799,7 @@ extern "C" HRESULT CacheSetLastUsedSource(
    // If the source path ends with the relative path then this source could be a new path.
    iSourceRelativePath = cchSourcePath - cchRelativePath;
-    if (CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, wzSourcePath + iSourceRelativePath, -1, wzRelativePath, -1))
+    if (CSTR_EQUAL == ::CompareStringOrdinal(wzSourcePath + iSourceRelativePath, -1, wzRelativePath, -1, TRUE))
    {
        hr = StrAllocString(&sczSourceFolder, wzSourcePath, iSourceRelativePath);
        ExitOnFailure(hr, "Failed to trim source folder.");
@@ -799,7 +807,7 @@ extern "C" HRESULT CacheSetLastUsedSource(
        hr = VariableGetString(pVariables, BURN_BUNDLE_LAST_USED_SOURCE, &sczLastSourceFolder);
        if (SUCCEEDED(hr))
        {
-            nCompare = ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, sczSourceFolder, -1, sczLastSourceFolder, -1);
+            nCompare = ::CompareStringOrdinal(sczSourceFolder, -1, sczLastSourceFolder, -1, TRUE);
        }
        else if (E_NOTFOUND == hr)
        {
@@ -851,6 +859,7 @@ extern "C" HRESULT CacheSendProgressCallback(
        case PROGRESS_STOP:
            hr = HRESULT_FROM_WIN32(ERROR_INSTALL_USEREXIT);
            ExitOnRootFailure(hr, "UX aborted on download progress.");
+            break;
        case PROGRESS_QUIET: // Not actually an error, just an indication to the caller to stop requesting progress.
            pCallback->pfnProgress = NULL;
@@ -860,6 +869,7 @@ extern "C" HRESULT CacheSendProgressCallback(
        default:
            hr = E_UNEXPECTED;
            ExitOnRootFailure(hr, "Invalid return code from progress routine.");
+            break;
        }
    }
@@ -1025,7 +1035,7 @@ extern "C" HRESULT CacheCompleteBundle(
    ExitOnFailure(hr, "Failed to combine completed path with engine file name.");
    // We can't just use wzExecutablePath because we needed to call CreateCompletedPath to ensure that the destination was secured.
-    Assert(CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, wzExecutablePath, -1, sczTargetPath, -1));
+    Assert(CSTR_EQUAL == ::CompareStringOrdinal(wzExecutablePath, -1, sczTargetPath, -1, TRUE));
    // If the bundle is running out of the package cache then we don't need to copy it there
    // (and don't want to since it'll be in use) so bail.
@@ -1429,8 +1439,8 @@ extern "C" void CacheUninitialize(
    ReleaseStr(pCache->sczBaseWorkingFolder);
    ReleaseStr(pCache->sczAcquisitionFolder);
    ReleaseStr(pCache->sczSourceProcessFolder);
-    ReleaseStr(pCache->sczBundleEngineWorkingPath)
+    ReleaseStr(pCache->sczBundleEngineWorkingPath);
-    ReleaseFileHandle(pCache->hBundleEngineWorkingFile)
+    ReleaseFileHandle(pCache->hBundleEngineWorkingFile);
    memset(pCache, 0, sizeof(BURN_CACHE));
 }
diff --git a/src/burn/engine/condition.cpp b/src/burn/engine/condition.cpp
index 8fa62f16..3719ce79 100644
--- a/src/burn/engine/condition.cpp
+++ b/src/burn/engine/condition.cpp
@@ -740,17 +740,17 @@ static HRESULT NextSymbol(
                    ::GetStringTypeW(CT_CTYPE1, &pContext->wzRead[n], 1, &charType);
                } while (C1_ALPHA & charType || C1_DIGIT & charType || L'_' == pContext->wzRead[n]);
-                if (2 == n && CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, pContext->wzRead, 2, L"OR", 2))
+                if (2 == n && CSTR_EQUAL == ::CompareStringOrdinal(pContext->wzRead, 2, L"OR", 2, TRUE))
                {
                    // OR
                    pContext->NextSymbol.Type = BURN_SYMBOL_TYPE_OR;
                }
-                else if (3 == n && CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, pContext->wzRead, 3, L"AND", 3))
+                else if (3 == n && CSTR_EQUAL == ::CompareStringOrdinal(pContext->wzRead, 3, L"AND", 3, TRUE))
                {
                    // AND
                    pContext->NextSymbol.Type = BURN_SYMBOL_TYPE_AND;
                }
-                else if (3 == n && CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, pContext->wzRead, 3, L"NOT", 3))
+                else if (3 == n && CSTR_EQUAL == ::CompareStringOrdinal(pContext->wzRead, 3, L"NOT", 3, TRUE))
                {
                    // NOT
                    pContext->NextSymbol.Type = BURN_SYMBOL_TYPE_NOT;
@@ -928,7 +928,7 @@ static HRESULT CompareStringValues(
    )
 {
    HRESULT hr = S_OK;
-    DWORD dwCompareString = (comparison & INSENSITIVE) ? NORM_IGNORECASE : 0;
+    BOOL fIgnoreCase = (comparison & INSENSITIVE) ? TRUE : FALSE;
    size_t cchLeftSize = 0;
    size_t cchRightSize = 0;
    int cchLeft = 0;
@@ -958,7 +958,7 @@ static HRESULT CompareStringValues(
    case BURN_SYMBOL_TYPE_EQ_I:
    case BURN_SYMBOL_TYPE_NE_I:
        {
-            int i = ::CompareStringW(LOCALE_INVARIANT, dwCompareString, wzLeftOperand, cchLeft, wzRightOperand, cchRight);
+            int i = ::CompareStringOrdinal(wzLeftOperand, cchLeft, wzRightOperand, cchRight, fIgnoreCase);
            hr = CompareIntegerValues(comparison, i, CSTR_EQUAL, pfResult);
        }
        break;
@@ -967,7 +967,7 @@ static HRESULT CompareStringValues(
        // test if left string contains right string
        for (int i = 0; (i + cchRight) <= cchLeft; ++i)
        {
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, dwCompareString, wzLeftOperand + i, cchRight, wzRightOperand, cchRight))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(wzLeftOperand + i, cchRight, wzRightOperand, cchRight, fIgnoreCase))
            {
                *pfResult = TRUE;
                ExitFunction();
@@ -978,12 +978,12 @@ static HRESULT CompareStringValues(
    case BURN_SYMBOL_TYPE_HIEQ:
    case BURN_SYMBOL_TYPE_HIEQ_I:
        // test if left string starts with right string
-        *pfResult = cchLeft >= cchRight && CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, dwCompareString, wzLeftOperand, cchRight, wzRightOperand, cchRight);
+        *pfResult = cchLeft >= cchRight && CSTR_EQUAL == ::CompareStringOrdinal(wzLeftOperand, cchRight, wzRightOperand, cchRight, fIgnoreCase);
        break;
    case BURN_SYMBOL_TYPE_LOEQ:
    case BURN_SYMBOL_TYPE_LOEQ_I:
        // test if left string ends with right string
-        *pfResult = cchLeft >= cchRight && CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, dwCompareString, wzLeftOperand + (cchLeft - cchRight), cchRight, wzRightOperand, cchRight);
+        *pfResult = cchLeft >= cchRight && CSTR_EQUAL == ::CompareStringOrdinal(wzLeftOperand + (cchLeft - cchRight), cchRight, wzRightOperand, cchRight, fIgnoreCase);
        break;
    default:
        ExitFunction1(hr = E_INVALIDARG);
diff --git a/src/burn/engine/container.cpp b/src/burn/engine/container.cpp
index fad010cf..41ab0919 100644
--- a/src/burn/engine/container.cpp
+++ b/src/burn/engine/container.cpp
@@ -400,7 +400,7 @@ extern "C" HRESULT ContainerFindById(
    {
        pContainer = &pContainers->rgContainers[i];
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, pContainer->sczId, -1, wzId, -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(pContainer->sczId, -1, wzId, -1, FALSE))
        {
            *ppContainer = pContainer;
            ExitFunction1(hr = S_OK);
diff --git a/src/burn/engine/core.cpp b/src/burn/engine/core.cpp
index b20f7f0c..2dfa4857 100644
--- a/src/burn/engine/core.cpp
+++ b/src/burn/engine/core.cpp
@@ -1215,8 +1215,8 @@ HRESULT CoreAppendLogToCommandLine(
        if (rgszArgs[i][0] == L'-' || rgszArgs[i][0] == L'/')
        {
            // Now looking for 'log' or 'l'
-            if ((CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &rgszArgs[i][1], -1, L"log", -1))
+            if ((CSTR_EQUAL == ::CompareStringOrdinal(&rgszArgs[i][1], -1, L"log", -1, TRUE))
-                || (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &rgszArgs[i][1], -1, L"l", -1)))
+                || (CSTR_EQUAL == ::CompareStringOrdinal(&rgszArgs[i][1], -1, L"l", -1, TRUE)))
            {
                ExitFunction1(hr = S_FALSE);
            }
@@ -1232,8 +1232,11 @@ HRESULT CoreAppendLogToCommandLine(
    hr = StrAllocConcat(psczCommandLine, szLogArgFormatted, 0);
    ExitOnFailure(hr, "Failed concatenating '-log' to command line");
-    hr = StrAllocConcat(psczObfuscatedCommandLine, szLogArgFormatted, 0);
+    if (psczObfuscatedCommandLine)
-    ExitOnFailure(hr, "Failed concatenating '-log' to obfuscated command line");
+    {
+        hr = StrAllocConcat(psczObfuscatedCommandLine, szLogArgFormatted, 0);
+        ExitOnFailure(hr, "Failed concatenating '-log' to obfuscated command line");
+    }
 LExit:
    if (rgszArgs)
@@ -1360,13 +1363,13 @@ extern "C" HRESULT CoreParseCommandLine(
        if (argv[i][0] == L'-' || argv[i][0] == L'/')
        {
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"l", -1) ||
+            if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"l", -1, TRUE) ||
-                CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"log", -1) ||
+                CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"log", -1, TRUE) ||
-                CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"xlog", -1))
+                CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"xlog", -1, TRUE))
            {
                pInternalCommand->dwLoggingAttributes &= ~BURN_LOGGING_ATTRIBUTE_APPEND;
-                if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], 1, L"x", 1))
+                if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], 1, L"x", 1, TRUE))
                {
                    pInternalCommand->dwLoggingAttributes |= BURN_LOGGING_ATTRIBUTE_VERBOSE | BURN_LOGGING_ATTRIBUTE_EXTRADEBUG;
                }
@@ -1382,24 +1385,24 @@ extern "C" HRESULT CoreParseCommandLine(
                hr = PathExpand(&pInternalCommand->sczLogFile, argv[i], PATH_EXPAND_FULLPATH);
                ExitOnFailure(hr, "Failed to copy log file path.");
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"?", -1) ||
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"?", -1, TRUE) ||
-                     CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"h", -1) ||
+                     CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"h", -1, TRUE) ||
-                     CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"help", -1))
+                     CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"help", -1, TRUE))
            {
                pCommand->action = BOOTSTRAPPER_ACTION_HELP;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"q", -1) ||
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"q", -1, TRUE) ||
-                     CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"quiet", -1) ||
+                     CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"quiet", -1, TRUE) ||
-                     CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"s", -1) ||
+                     CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"s", -1, TRUE) ||
-                     CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"silent", -1))
+                     CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"silent", -1, TRUE))
            {
                pCommand->display = BOOTSTRAPPER_DISPLAY_NONE;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"passive", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"passive", -1, TRUE))
            {
                pCommand->display = BOOTSTRAPPER_DISPLAY_PASSIVE;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"layout", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"layout", -1, TRUE))
            {
                if (BOOTSTRAPPER_ACTION_HELP != pCommand->action)
                {
@@ -1415,47 +1418,47 @@ extern "C" HRESULT CoreParseCommandLine(
                    ExitOnFailure(hr, "Failed to copy path for layout directory.");
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"unsafeuninstall", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"unsafeuninstall", -1, TRUE))
            {
                if (BOOTSTRAPPER_ACTION_HELP != pCommand->action)
                {
                    pCommand->action = BOOTSTRAPPER_ACTION_UNSAFE_UNINSTALL;
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"uninstall", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"uninstall", -1, TRUE))
            {
                if (BOOTSTRAPPER_ACTION_HELP != pCommand->action)
                {
                    pCommand->action = BOOTSTRAPPER_ACTION_UNINSTALL;
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"repair", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"repair", -1, TRUE))
            {
                if (BOOTSTRAPPER_ACTION_HELP != pCommand->action)
                {
                    pCommand->action = BOOTSTRAPPER_ACTION_REPAIR;
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"modify", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"modify", -1, TRUE))
            {
                if (BOOTSTRAPPER_ACTION_HELP != pCommand->action)
                {
                    pCommand->action = BOOTSTRAPPER_ACTION_MODIFY;
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"package", -1) ||
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"package", -1, TRUE) ||
-                     CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"update", -1))
+                     CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"update", -1, TRUE))
            {
                if (BOOTSTRAPPER_ACTION_UNKNOWN == pCommand->action)
                {
                    pCommand->action = BOOTSTRAPPER_ACTION_INSTALL;
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"noaupause", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"noaupause", -1, TRUE))
            {
                pInternalCommand->automaticUpdates = BURN_AU_PAUSE_ACTION_NONE;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"keepaupaused", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"keepaupaused", -1, TRUE))
            {
                // Switch /noaupause takes precedence.
                if (BURN_AU_PAUSE_ACTION_NONE != pInternalCommand->automaticUpdates)
@@ -1463,11 +1466,11 @@ extern "C" HRESULT CoreParseCommandLine(
                    pInternalCommand->automaticUpdates = BURN_AU_PAUSE_ACTION_IFELEVATED_NORESUME;
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"disablesystemrestore", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"disablesystemrestore", -1, TRUE))
            {
                pInternalCommand->fDisableSystemRestore = TRUE;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, L"originalsource", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, L"originalsource", -1, TRUE))
            {
                if (i + 1 >= argc)
                {
@@ -1479,7 +1482,7 @@ extern "C" HRESULT CoreParseCommandLine(
                hr = PathExpand(&pInternalCommand->sczOriginalSource, argv[i], PATH_EXPAND_FULLPATH);
                ExitOnFailure(hr, "Failed to copy last used source.");
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_PARENT, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_PARENT, -1, TRUE))
            {
                if (i + 1 >= argc)
                {
@@ -1492,12 +1495,12 @@ extern "C" HRESULT CoreParseCommandLine(
                hr = StrAllocString(&pInternalCommand->sczActiveParent, argv[i], 0);
                ExitOnFailure(hr, "Failed to copy parent.");
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_PARENT_NONE, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_PARENT_NONE, -1, TRUE))
            {
                hr = StrAllocString(&pInternalCommand->sczActiveParent, L"", 0);
                ExitOnFailure(hr, "Failed to initialize parent to none.");
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_LOG_APPEND, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_LOG_APPEND, -1, TRUE))
            {
                if (i + 1 >= argc)
                {
@@ -1512,7 +1515,7 @@ extern "C" HRESULT CoreParseCommandLine(
                pInternalCommand->dwLoggingAttributes |= BURN_LOGGING_ATTRIBUTE_APPEND;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_LOG_MODE), BURN_COMMANDLINE_SWITCH_LOG_MODE, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_LOG_MODE), BURN_COMMANDLINE_SWITCH_LOG_MODE, -1, TRUE))
            {
                // Get a pointer to the next character after the switch.
                LPCWSTR wzParam = &argv[i][2 + lstrlenW(BURN_COMMANDLINE_SWITCH_LOG_MODE)];
@@ -1541,7 +1544,7 @@ extern "C" HRESULT CoreParseCommandLine(
                    }
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_ELEVATED, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_ELEVATED, -1, TRUE))
            {
                if (i + 3 >= argc)
                {
@@ -1579,7 +1582,7 @@ extern "C" HRESULT CoreParseCommandLine(
                i += 2;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_SYSTEM_COMPONENT), BURN_COMMANDLINE_SWITCH_SYSTEM_COMPONENT, lstrlenW(BURN_COMMANDLINE_SWITCH_SYSTEM_COMPONENT)))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_SYSTEM_COMPONENT), BURN_COMMANDLINE_SWITCH_SYSTEM_COMPONENT, lstrlenW(BURN_COMMANDLINE_SWITCH_SYSTEM_COMPONENT), TRUE))
            {
                // Get a pointer to the next character after the switch.
                LPCWSTR wzParam = &argv[i][1 + lstrlenW(BURN_COMMANDLINE_SWITCH_SYSTEM_COMPONENT)];
@@ -1602,7 +1605,7 @@ extern "C" HRESULT CoreParseCommandLine(
                    pInternalCommand->fArpSystemComponent = TRUE;
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_EMBEDDED, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_EMBEDDED, -1, TRUE))
            {
                if (i + 3 >= argc)
                {
@@ -1633,59 +1636,59 @@ extern "C" HRESULT CoreParseCommandLine(
                i += 2;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_DETECT, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_DETECT, -1, TRUE))
            {
                pCommand->relationType = BOOTSTRAPPER_RELATION_DETECT;
                LogId(REPORT_STANDARD, MSG_BURN_RUN_BY_RELATED_BUNDLE, LoggingRelationTypeToString(pCommand->relationType));
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_UPGRADE, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_UPGRADE, -1, TRUE))
            {
                pCommand->relationType = BOOTSTRAPPER_RELATION_UPGRADE;
                LogId(REPORT_STANDARD, MSG_BURN_RUN_BY_RELATED_BUNDLE, LoggingRelationTypeToString(pCommand->relationType));
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_ADDON, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_ADDON, -1, TRUE))
            {
                pCommand->relationType = BOOTSTRAPPER_RELATION_ADDON;
                LogId(REPORT_STANDARD, MSG_BURN_RUN_BY_RELATED_BUNDLE, LoggingRelationTypeToString(pCommand->relationType));
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_DEPENDENT_ADDON, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_DEPENDENT_ADDON, -1, TRUE))
            {
                pCommand->relationType = BOOTSTRAPPER_RELATION_DEPENDENT_ADDON;
                LogId(REPORT_STANDARD, MSG_BURN_RUN_BY_RELATED_BUNDLE, LoggingRelationTypeToString(pCommand->relationType));
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_PATCH, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_PATCH, -1, TRUE))
            {
                pCommand->relationType = BOOTSTRAPPER_RELATION_PATCH;
                LogId(REPORT_STANDARD, MSG_BURN_RUN_BY_RELATED_BUNDLE, LoggingRelationTypeToString(pCommand->relationType));
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_DEPENDENT_PATCH, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_DEPENDENT_PATCH, -1, TRUE))
            {
                pCommand->relationType = BOOTSTRAPPER_RELATION_DEPENDENT_PATCH;
                LogId(REPORT_STANDARD, MSG_BURN_RUN_BY_RELATED_BUNDLE, LoggingRelationTypeToString(pCommand->relationType));
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_UPDATE, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_UPDATE, -1, TRUE))
            {
                pCommand->relationType = BOOTSTRAPPER_RELATION_UPDATE;
                LogId(REPORT_STANDARD, MSG_BURN_RUN_BY_RELATED_BUNDLE, LoggingRelationTypeToString(pCommand->relationType));
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_CHAIN_PACKAGE, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RELATED_CHAIN_PACKAGE, -1, TRUE))
            {
                pCommand->relationType = BOOTSTRAPPER_RELATION_CHAIN_PACKAGE;
                LogId(REPORT_STANDARD, MSG_BURN_RUN_BY_RELATED_BUNDLE, LoggingRelationTypeToString(pCommand->relationType));
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_PASSTHROUGH, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_PASSTHROUGH, -1, TRUE))
            {
                pCommand->fPassthrough = TRUE;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RUNONCE, -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], -1, BURN_COMMANDLINE_SWITCH_RUNONCE, -1, TRUE))
            {
                switch (pInternalCommand->mode)
                {
@@ -1698,7 +1701,7 @@ extern "C" HRESULT CoreParseCommandLine(
                    TraceLog(E_INVALIDARG, "Multiple mode command-line switches were provided.");
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_IGNOREDEPENDENCIES), BURN_COMMANDLINE_SWITCH_IGNOREDEPENDENCIES, lstrlenW(BURN_COMMANDLINE_SWITCH_IGNOREDEPENDENCIES)))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_IGNOREDEPENDENCIES), BURN_COMMANDLINE_SWITCH_IGNOREDEPENDENCIES, lstrlenW(BURN_COMMANDLINE_SWITCH_IGNOREDEPENDENCIES), TRUE))
            {
                // Get a pointer to the next character after the switch.
                LPCWSTR wzParam = &argv[i][1 + lstrlenW(BURN_COMMANDLINE_SWITCH_IGNOREDEPENDENCIES)];
@@ -1713,7 +1716,7 @@ extern "C" HRESULT CoreParseCommandLine(
                    ExitOnFailure(hr, "Failed to allocate the list of dependencies to ignore.");
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_ANCESTORS), BURN_COMMANDLINE_SWITCH_ANCESTORS, lstrlenW(BURN_COMMANDLINE_SWITCH_ANCESTORS)))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_ANCESTORS), BURN_COMMANDLINE_SWITCH_ANCESTORS, lstrlenW(BURN_COMMANDLINE_SWITCH_ANCESTORS), TRUE))
            {
                // Get a pointer to the next character after the switch.
                LPCWSTR wzParam = &argv[i][1 + lstrlenW(BURN_COMMANDLINE_SWITCH_ANCESTORS)];
@@ -1728,7 +1731,7 @@ extern "C" HRESULT CoreParseCommandLine(
                    ExitOnFailure(hr, "Failed to allocate the list of ancestors.");
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_WORKING_DIRECTORY), BURN_COMMANDLINE_SWITCH_WORKING_DIRECTORY, lstrlenW(BURN_COMMANDLINE_SWITCH_WORKING_DIRECTORY)))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_WORKING_DIRECTORY), BURN_COMMANDLINE_SWITCH_WORKING_DIRECTORY, lstrlenW(BURN_COMMANDLINE_SWITCH_WORKING_DIRECTORY), TRUE))
            {
                // Get a pointer to the next character after the switch.
                LPCWSTR wzParam = &argv[i][1 + lstrlenW(BURN_COMMANDLINE_SWITCH_WORKING_DIRECTORY)];
@@ -1743,7 +1746,7 @@ extern "C" HRESULT CoreParseCommandLine(
                    ExitOnFailure(hr, "Failed to store the custom working directory.");
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_FILEHANDLE_ATTACHED), BURN_COMMANDLINE_SWITCH_FILEHANDLE_ATTACHED, lstrlenW(BURN_COMMANDLINE_SWITCH_FILEHANDLE_ATTACHED)))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_FILEHANDLE_ATTACHED), BURN_COMMANDLINE_SWITCH_FILEHANDLE_ATTACHED, lstrlenW(BURN_COMMANDLINE_SWITCH_FILEHANDLE_ATTACHED), TRUE))
            {
                LPCWSTR wzParam = &argv[i][2 + lstrlenW(BURN_COMMANDLINE_SWITCH_FILEHANDLE_ATTACHED)];
                if (L'=' != wzParam[-1] || L'\0' == wzParam[0])
@@ -1765,7 +1768,7 @@ extern "C" HRESULT CoreParseCommandLine(
                    }
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_FILEHANDLE_SELF), BURN_COMMANDLINE_SWITCH_FILEHANDLE_SELF, lstrlenW(BURN_COMMANDLINE_SWITCH_FILEHANDLE_SELF)))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_FILEHANDLE_SELF), BURN_COMMANDLINE_SWITCH_FILEHANDLE_SELF, lstrlenW(BURN_COMMANDLINE_SWITCH_FILEHANDLE_SELF), TRUE))
            {
                LPCWSTR wzParam = &argv[i][2 + lstrlenW(BURN_COMMANDLINE_SWITCH_FILEHANDLE_SELF)];
                if (L'=' != wzParam[-1] || L'\0' == wzParam[0])
@@ -1787,7 +1790,7 @@ extern "C" HRESULT CoreParseCommandLine(
                    }
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_SPLASH_SCREEN), BURN_COMMANDLINE_SWITCH_SPLASH_SCREEN, lstrlenW(BURN_COMMANDLINE_SWITCH_SPLASH_SCREEN)))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_SPLASH_SCREEN), BURN_COMMANDLINE_SWITCH_SPLASH_SCREEN, lstrlenW(BURN_COMMANDLINE_SWITCH_SPLASH_SCREEN), TRUE))
            {
                LPCWSTR wzParam = &argv[i][2 + lstrlenW(BURN_COMMANDLINE_SWITCH_SPLASH_SCREEN)];
                if (L'=' != wzParam[-1] || L'\0' == wzParam[0])
@@ -1809,7 +1812,7 @@ extern "C" HRESULT CoreParseCommandLine(
                    }
                }
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, &argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_PREFIX), BURN_COMMANDLINE_SWITCH_PREFIX, lstrlenW(BURN_COMMANDLINE_SWITCH_PREFIX)))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(&argv[i][1], lstrlenW(BURN_COMMANDLINE_SWITCH_PREFIX), BURN_COMMANDLINE_SWITCH_PREFIX, lstrlenW(BURN_COMMANDLINE_SWITCH_PREFIX), TRUE))
            {
                // Skip (but log) any other private burn switches we don't recognize, so that
                // adding future private variables doesn't break old bundles
diff --git a/src/burn/engine/core.h b/src/burn/engine/core.h
index c5d0a370..cf615e35 100644
--- a/src/burn/engine/core.h
+++ b/src/burn/engine/core.h
@@ -46,6 +46,8 @@ const LPCWSTR BURN_BUNDLE_FORCED_RESTART_PACKAGE = L"WixBundleForcedRestartPacka
 const LPCWSTR BURN_BUNDLE_INSTALLED = L"WixBundleInstalled";
 const LPCWSTR BURN_BUNDLE_ELEVATED = L"WixBundleElevated";
 const LPCWSTR BURN_BUNDLE_PROVIDER_KEY = L"WixBundleProviderKey";
+const LPCWSTR BURN_BUNDLE_SOURCE_PROCESS_PATH = L"WixBundleSourceProcessPath";
+const LPCWSTR BURN_BUNDLE_SOURCE_PROCESS_FOLDER = L"WixBundleSourceProcessFolder";
 const LPCWSTR BURN_BUNDLE_TAG = L"WixBundleTag";
 const LPCWSTR BURN_BUNDLE_UILEVEL = L"WixBundleUILevel";
 const LPCWSTR BURN_BUNDLE_VERSION = L"WixBundleVersion";
diff --git a/src/burn/engine/dependency.cpp b/src/burn/engine/dependency.cpp
index f398a070..94a8a1e4 100644
--- a/src/burn/engine/dependency.cpp
+++ b/src/burn/engine/dependency.cpp
@@ -263,7 +263,7 @@ extern "C" HRESULT DependencyDetectProviderKeyBundleCode(
        hr = StrAllocString(&pRegistration->sczDetectedProviderKeyBundleCode, pRegistration->sczProviderKey, 0);
        ExitOnFailure(hr, "Failed to initialize provider key bundle code.");
    }
-    else if (CSTR_EQUAL != ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pRegistration->sczCode, -1, pRegistration->sczDetectedProviderKeyBundleCode, -1))
+    else if (CSTR_EQUAL != ::CompareStringOrdinal(pRegistration->sczCode, -1, pRegistration->sczDetectedProviderKeyBundleCode, -1, TRUE))
    {
        pRegistration->fDetectedForeignProviderKeyBundleCode = TRUE;
        LogId(REPORT_STANDARD, MSG_DETECTED_FOREIGN_BUNDLE_PROVIDER_REGISTRATION, pRegistration->sczProviderKey, pRegistration->sczDetectedProviderKeyBundleCode);
@@ -293,12 +293,12 @@ extern "C" HRESULT DependencyDetectBundle(
        {
            DEPENDENCY* pDependent = pRegistration->rgDependents + i;
-            if (pDependencies->fActiveParent && CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pDependencies->wzActiveParent, -1, pDependent->sczKey, -1))
+            if (pDependencies->fActiveParent && CSTR_EQUAL == ::CompareStringOrdinal(pDependencies->wzActiveParent, -1, pDependent->sczKey, -1, TRUE))
            {
                pRegistration->fParentRegisteredAsDependent = TRUE;
            }
-            if (pDependencies->fSelfDependent && CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pDependencies->wzSelfDependent, -1, pDependent->sczKey, -1))
+            if (pDependencies->fSelfDependent && CSTR_EQUAL == ::CompareStringOrdinal(pDependencies->wzSelfDependent, -1, pDependent->sczKey, -1, TRUE))
            {
                pRegistration->fSelfRegisteredAsDependent = TRUE;
            }
@@ -419,6 +419,7 @@ extern "C" HRESULT DependencyPlanPackageBegin(
    STRINGDICT_HANDLE sdIgnoredDependents = NULL;
    BURN_DEPENDENCY_ACTION dependencyExecuteAction = BURN_DEPENDENCY_ACTION_NONE;
    BURN_DEPENDENCY_ACTION dependencyRollbackAction = BURN_DEPENDENCY_ACTION_NONE;
+    BOOL fDependenciesForcedAbsent = FALSE;
    BOOL fDependentBlocksUninstall = FALSE;
    BOOL fAttemptingUninstall = BOOTSTRAPPER_ACTION_STATE_UNINSTALL == pPackage->execute || pPackage->compatiblePackage.fRemove;
@@ -467,7 +468,16 @@ extern "C" HRESULT DependencyPlanPackageBegin(
                {
                    hr = S_OK;
-                    if (!fDependentBlocksUninstall)
+                    if (BOOTSTRAPPER_REQUEST_STATE_FORCE_ABSENT == pPackage->requested)
+                    {
+                        if (!fDependenciesForcedAbsent)
+                        {
+                            fDependenciesForcedAbsent = TRUE;
+                            LogId(REPORT_STANDARD, MSG_DEPENDENCY_PACKAGE_DEPENDENTS_OVERRIDDEN, pPackage->sczId);
+                        }
+                    }
+                    else if (!fDependentBlocksUninstall)
                    {
                        fDependentBlocksUninstall = TRUE;
@@ -591,8 +601,8 @@ extern "C" HRESULT DependencyPlanPackageBegin(
            pProvider->dependentExecute = BURN_DEPENDENCY_ACTION_NONE;
        }
-        if (BURN_DEPENDENCY_ACTION_UNREGISTER == pProvider->dependentRollback && pProvider->fBundleRegisteredAsDependent ||
+        if ((BURN_DEPENDENCY_ACTION_UNREGISTER == pProvider->dependentRollback && pProvider->fBundleRegisteredAsDependent) ||
-            BURN_DEPENDENCY_ACTION_REGISTER == pProvider->dependentRollback && !pProvider->fBundleRegisteredAsDependent)
+            (BURN_DEPENDENCY_ACTION_REGISTER == pProvider->dependentRollback && !pProvider->fBundleRegisteredAsDependent))
        {
            pProvider->dependentRollback = BURN_DEPENDENCY_ACTION_NONE;
        }
@@ -905,7 +915,7 @@ extern "C" HRESULT DependencyDetectCompatibleEntry(
                continue;
            }
        }
-        else if (sczId && CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, wzPackageProviderId, -1, sczId, -1))
+        else if (sczId && CSTR_EQUAL == ::CompareStringOrdinal(wzPackageProviderId, -1, sczId, -1, TRUE))
        {
            continue;
        }
@@ -969,7 +979,7 @@ static HRESULT DetectPackageDependents(
        {
            DEPENDENCY* pDependent = pProvider->rgDependents + iDependent;
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pRegistration->sczCode, -1, pDependent->sczKey, -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(pRegistration->sczCode, -1, pDependent->sczKey, -1, TRUE))
            {
                pProvider->fBundleRegisteredAsDependent = TRUE;
                fBundleRegisteredAsDependent = TRUE;
@@ -1043,7 +1053,7 @@ static HRESULT SplitIgnoreDependencies(
            hr = DictAddKey(sdIgnoreDependencies, wzToken);
            ExitOnFailure(hr, "Failed to add \"%ls\" to the string dictionary.", wzToken);
-            if (!*pfIgnoreAll && CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, L"ALL", -1, wzToken, -1))
+            if (!*pfIgnoreAll && CSTR_EQUAL == ::CompareStringOrdinal(L"ALL", -1, wzToken, -1, TRUE))
            {
                *pfIgnoreAll = TRUE;
            }
diff --git a/src/burn/engine/detect.cpp b/src/burn/engine/detect.cpp
index 08f6b57c..c19d382c 100644
--- a/src/burn/engine/detect.cpp
+++ b/src/burn/engine/detect.cpp
@@ -130,7 +130,7 @@ extern "C" HRESULT DetectForwardCompatibleBundles(
            BURN_RELATED_BUNDLE* pRelatedBundle = pRegistration->relatedBundles.rgRelatedBundles + iRelatedBundle;
            if (BOOTSTRAPPER_RELATION_UPGRADE == pRelatedBundle->detectRelationType &&
-                CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pRegistration->sczDetectedProviderKeyBundleCode, -1, pRelatedBundle->package.sczId, -1))
+                CSTR_EQUAL == ::CompareStringOrdinal(pRegistration->sczDetectedProviderKeyBundleCode, -1, pRelatedBundle->package.sczId, -1, TRUE))
            {
                hr = VerCompareParsedVersions(pRegistration->pVersion, pRelatedBundle->pVersion, &nCompareResult);
                ExitOnFailure(hr, "Failed to compare bundle version '%ls' to related bundle version '%ls'", pRegistration->pVersion->sczVersion, pRelatedBundle->pVersion->sczVersion);
diff --git a/src/burn/engine/elevation.cpp b/src/burn/engine/elevation.cpp
index 90e9db01..ef87841f 100644
--- a/src/burn/engine/elevation.cpp
+++ b/src/burn/engine/elevation.cpp
@@ -1452,9 +1452,9 @@ extern "C" HRESULT ElevationExecutePackageDependencyAction(
    ExitOnFailure(hr, "Failed to write bundle dependency key to message buffer.");
    // Dependent actions.
-    for (DWORD i = 0; i < pExecuteAction->packageProvider.pPackage->cDependencyProviders; ++i)
+    for (DWORD i = 0; i < pExecuteAction->packageDependency.pPackage->cDependencyProviders; ++i)
    {
-        BURN_DEPENDENCY_PROVIDER* pProvider = pExecuteAction->packageProvider.pPackage->rgDependencyProviders + i;
+        BURN_DEPENDENCY_PROVIDER* pProvider = pExecuteAction->packageDependency.pPackage->rgDependencyProviders + i;
        BURN_DEPENDENCY_ACTION* pAction = fRollback ? &pProvider->dependentRollback : &pProvider->dependentExecute;
        hr = BuffWriteNumber(&pbData, &cbData, (DWORD)*pAction);
        ExitOnFailure(hr, "Failed to write dependent action to message buffer.");
@@ -2824,7 +2824,7 @@ LExit:
    // TODO: do the right thing here.
    //DependencyUninitializeRegistrationAction(&action);
    ReleaseStr(action.sczDependentProviderKey);
-    ReleaseStr(action.sczBundleCode)
+    ReleaseStr(action.sczBundleCode);
    return hr;
 }
@@ -3380,7 +3380,7 @@ static HRESULT OnUninstallMsiCompatiblePackage(
    }
    if (!sczCompatiblePackageId || !*sczCompatiblePackageId ||
-        CSTR_EQUAL != ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pCompatiblePackage->compatibleEntry.sczId, -1, sczCompatiblePackageId, -1))
+        CSTR_EQUAL != ::CompareStringOrdinal(pCompatiblePackage->compatibleEntry.sczId, -1, sczCompatiblePackageId, -1, TRUE))
    {
        ExitWithRootFailure(hr, E_INVALIDARG, "Package '%ls' has no compatible package with id: %ls", sczPackageId, sczCompatiblePackageId);
    }
@@ -3486,9 +3486,9 @@ static HRESULT OnExecutePackageDependencyAction(
    ExitOnFailure(hr, "Failed to read bundle dependency key from message buffer.");
    // Read dependent actions.
-    for (DWORD i = 0; i < executeAction.packageProvider.pPackage->cDependencyProviders; ++i)
+    for (DWORD i = 0; i < executeAction.packageDependency.pPackage->cDependencyProviders; ++i)
    {
-        BURN_DEPENDENCY_PROVIDER* pProvider = executeAction.packageProvider.pPackage->rgDependencyProviders + i;
+        BURN_DEPENDENCY_PROVIDER* pProvider = executeAction.packageDependency.pPackage->rgDependencyProviders + i;
        BURN_DEPENDENCY_ACTION* pAction = fRollback ? &pProvider->dependentRollback : &pProvider->dependentExecute;
        hr = BuffReadNumber(pbData, cbData, &iData, (DWORD*)pAction);
        ExitOnFailure(hr, "Failed to read dependent action.");
@@ -3792,7 +3792,7 @@ static HRESULT OnCleanCompatiblePackage(
    }
    if (!sczCompatiblePackageId || !*sczCompatiblePackageId ||
-        CSTR_EQUAL != ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pCompatiblePackage->compatibleEntry.sczId, -1, sczCompatiblePackageId, -1))
+        CSTR_EQUAL != ::CompareStringOrdinal(pCompatiblePackage->compatibleEntry.sczId, -1, sczCompatiblePackageId, -1, TRUE))
    {
        ExitWithRootFailure(hr, E_INVALIDARG, "Package '%ls' has no compatible package with id: %ls", sczPackageId, sczCompatiblePackageId);
    }
@@ -3876,7 +3876,7 @@ static HRESULT OnLaunchApprovedExe(
    hr = RegReadString(hKey, pApprovedExe->sczValueName, &pLaunchApprovedExe->sczExecutablePath);
    ExitOnFailure(hr, "Failed to read the value for the approved exe path.");
-    hr = ApprovedExesVerifySecureLocation(pCache, pVariables, pLaunchApprovedExe->sczExecutablePath);
+    hr = ApprovedExesVerifySecureLocation(pCache, pVariables, pLaunchApprovedExe->sczExecutablePath, 0, NULL);
    ExitOnFailure(hr, "Failed to verify the executable path is in a secure location: %ls", pLaunchApprovedExe->sczExecutablePath);
    if (S_FALSE == hr)
    {
diff --git a/src/burn/engine/engine.cpp b/src/burn/engine/engine.cpp
index c372772c..d432f732 100644
--- a/src/burn/engine/engine.cpp
+++ b/src/burn/engine/engine.cpp
@@ -379,7 +379,8 @@ static HRESULT InitializeEngineState(
    BurnPipeConnectionInitialize(&pEngineState->embeddedConnection);
    // Retain whether bundle was initially run elevated.
-    ProcElevated(::GetCurrentProcess(), &pEngineState->internalCommand.fInitiallyElevated);
+    hr = ProcIsHighIntegrity(::GetCurrentProcess(), &pEngineState->internalCommand.fInitiallyElevated);
+    ExitOnFailure(hr, "Failed to determine if process is running elevated.");
    // Parse command line.
    hr = CoreParseCommandLine(&pEngineState->internalCommand, &pEngineState->command, &pEngineState->companionConnection, &pEngineState->embeddedConnection, &hSectionFile, &hSourceEngineFile);
diff --git a/src/burn/engine/engine.mc b/src/burn/engine/engine.mc
index c7a07385..776f7832 100644
--- a/src/burn/engine/engine.mc
+++ b/src/burn/engine/engine.mc
@@ -1282,3 +1282,9 @@ Language=English
 Skipping MSI property '%1!ls!' because condition '%2!ls!' evaluates to %3!hs!.
 .
+MessageId=701
+Severity=Warning
+SymbolicName=MSG_DEPENDENCY_PACKAGE_DEPENDENTS_OVERRIDDEN
+Language=English
+BA requested to uninstall package: %1!ls!, despite dependents:
+.
diff --git a/src/burn/engine/engine.vcxproj b/src/burn/engine/engine.vcxproj
index 249f8eef..98556ea6 100644
--- a/src/burn/engine/engine.vcxproj
+++ b/src/burn/engine/engine.vcxproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
-<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup Label="ProjectConfigurations">
    <ProjectConfiguration Include="Debug|Win32">
      <Configuration>Debug</Configuration>
diff --git a/src/burn/engine/exeengine.cpp b/src/burn/engine/exeengine.cpp
index 85168943..c001e563 100644
--- a/src/burn/engine/exeengine.cpp
+++ b/src/burn/engine/exeengine.cpp
@@ -25,15 +25,15 @@ extern "C" HRESULT ExeEngineParsePackageFromXml(
    hr = XmlGetAttributeEx(pixnExePackage, L"DetectionType", &scz);
    ExitOnRequiredXmlQueryFailure(hr, "Failed to get @DetectionType.");
-    if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"condition", -1))
+    if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"condition", -1, FALSE))
    {
        pPackage->Exe.detectionType = BURN_EXE_DETECTION_TYPE_CONDITION;
    }
-    else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"arp", -1))
+    else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"arp", -1, FALSE))
    {
        pPackage->Exe.detectionType = BURN_EXE_DETECTION_TYPE_ARP;
    }
-    else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"none", -1))
+    else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"none", -1, FALSE))
    {
        pPackage->Exe.detectionType = BURN_EXE_DETECTION_TYPE_NONE;
    }
@@ -114,15 +114,15 @@ extern "C" HRESULT ExeEngineParsePackageFromXml(
    if (fFoundXml)
    {
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"burn", -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"burn", -1, FALSE))
        {
            pPackage->Exe.protocol = BURN_EXE_PROTOCOL_TYPE_BURN;
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"netfx4", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"netfx4", -1, FALSE))
        {
            pPackage->Exe.protocol = BURN_EXE_PROTOCOL_TYPE_NETFX4;
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"none", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"none", -1, FALSE))
        {
            pPackage->Exe.protocol = BURN_EXE_PROTOCOL_TYPE_NONE;
        }
@@ -449,7 +449,7 @@ extern "C" HRESULT ExeEngineExecutePackage(
    if (BURN_EXE_DETECTION_TYPE_ARP == pPackage->Exe.detectionType &&
        (BOOTSTRAPPER_ACTION_STATE_UNINSTALL == pExecuteAction->exePackage.action ||
-        BOOTSTRAPPER_ACTION_STATE_INSTALL == pExecuteAction->exePackage.action && fRollback))
+         (BOOTSTRAPPER_ACTION_STATE_INSTALL == pExecuteAction->exePackage.action && fRollback)))
    {
        hr = DetectArpEntry(pPackage, &applyState, &sczArpUninstallString);
        ExitOnFailure(hr, "Failed to query ArpEntry for %hs.", BOOTSTRAPPER_ACTION_STATE_UNINSTALL == pExecuteAction->exePackage.action ? "uninstall" : "install");
@@ -489,29 +489,30 @@ extern "C" HRESULT ExeEngineExecutePackage(
    }
    else if (BURN_EXE_DETECTION_TYPE_ARP == pPackage->Exe.detectionType && BOOTSTRAPPER_ACTION_STATE_UNINSTALL == pExecuteAction->exePackage.action)
    {
-        ExitOnNull(sczArpUninstallString, hr, E_INVALIDARG, "%hs is null.", pPackage->Exe.fArpUseUninstallString ? "UninstallString" : "QuietUninstallString");
+        LPCWSTR szRegName = pPackage->Exe.fArpUseUninstallString ? L"UninstallString" : L"QuietUninstallString";
+        ExitOnNull(sczArpUninstallString, hr, E_INVALIDARG, "%ls is null.", szRegName);
        hr = AppParseCommandLine(sczArpUninstallString, &argcArp, &argvArp);
-        ExitOnFailure(hr, "Failed to parse QuietUninstallString: %ls.", sczArpUninstallString);
+        ExitOnFailure(hr, "Failed to parse %ls: %ls.", szRegName, sczArpUninstallString);
-        ExitOnNull(argcArp, hr, E_INVALIDARG, "QuietUninstallString must contain an executable path.");
+        ExitOnNull(argcArp, hr, E_INVALIDARG, "%ls must contain an executable path.", szRegName);
        hr = StrAllocString(&sczExecutablePath, argvArp[0], 0);
        ExitOnFailure(hr, "Failed to copy executable path.");
        if (pPackage->fPerMachine)
        {
-            hr = ApprovedExesVerifySecureLocation(pCache, pVariables, sczExecutablePath);
+            hr = ApprovedExesVerifySecureLocation(pCache, pVariables, sczExecutablePath, argcArp - 1, (argcArp > 1) ? const_cast<LPCWSTR*>(argvArp + 1) : NULL);
-            ExitOnFailure(hr, "Failed to verify the QuietUninstallString executable path is in a secure location: %ls", sczExecutablePath);
+            ExitOnFailure(hr, "Failed to verify the %ls executable path is in a secure location: %ls", szRegName, sczExecutablePath);
            if (S_FALSE == hr)
            {
-                LogStringLine(REPORT_STANDARD, "The QuietUninstallString executable path is not in a secure location: %ls", sczExecutablePath);
+                LogStringLine(REPORT_STANDARD, "The %ls executable path is not in a secure location: %ls", szRegName, sczExecutablePath);
                ExitFunction1(hr = HRESULT_FROM_WIN32(ERROR_ACCESS_DENIED));
            }
        }
        hr = PathGetDirectory(sczExecutablePath, &sczCachedDirectory);
-        ExitOnFailure(hr, "Failed to get parent directory for QuietUninstallString executable path: %ls", sczExecutablePath);
+        ExitOnFailure(hr, "Failed to get parent directory for %ls executable path: %ls", szRegName, sczExecutablePath);
    }
    else
    {
@@ -587,13 +588,15 @@ extern "C" HRESULT ExeEngineExecutePackage(
    }
    // build base command
-    hr = StrAllocFormatted(&sczBaseCommand, L"\"%ls\"", sczExecutablePath);
+    if (sczArpUninstallString && *sczArpUninstallString)
-    ExitOnFailure(hr, "Failed to allocate base command.");
+    {
+        hr = StrAllocString(&sczBaseCommand, sczArpUninstallString, 0);
-    for (int i = 1; i < argcArp; ++i)
+        ExitOnFailure(hr, "Failed to allocate base command.");
+    }
+    else
    {
-        hr = AppAppendCommandLineArgument(&sczBaseCommand, argvArp[i]);
+        hr = StrAllocFormatted(&sczBaseCommand, L"\"%ls\"", sczExecutablePath);
-        ExitOnFailure(hr, "Failed to append argument from ARP.");
+        ExitOnFailure(hr, "Failed to allocate base command.");
    }
    if (pPackage->Exe.fBundle)
diff --git a/src/burn/engine/logging.cpp b/src/burn/engine/logging.cpp
index 60c16c01..52123499 100644
--- a/src/burn/engine/logging.cpp
+++ b/src/burn/engine/logging.cpp
@@ -322,15 +322,17 @@ extern "C" HRESULT LoggingSetPackageVariable(
        ExitFunction();
    }
-    // For burn packages we'll add logging even it it wasn't explictly specified
+    // For burn packages we'll add logging even it it wasn't explictly specified.
    if (BURN_PACKAGE_TYPE_BUNDLE == pPackage->type || (BURN_PACKAGE_TYPE_EXE == pPackage->type && BURN_EXE_PROTOCOL_TYPE_BURN == pPackage->Exe.protocol))
    {
        if (!fRollback && (!pPackage->sczLogPathVariable || !*pPackage->sczLogPathVariable))
        {
+            // Best effort, no need to fail if we can't set the logging path.
            StrAllocFormatted(&pPackage->sczLogPathVariable, L"WixBundleLog_%ls", pPackage->sczId);
        }
        else if (fRollback && (!pPackage->sczRollbackLogPathVariable || !*pPackage->sczRollbackLogPathVariable))
        {
+            // Best effort, no need to fail if we can't set the logging path.
            StrAllocFormatted(&pPackage->sczRollbackLogPathVariable, L"WixBundleRollbackLog_%ls", pPackage->sczId);
        }
    }
@@ -1052,7 +1054,8 @@ static HRESULT GetNonSessionSpecificTempFolder(
        hr = ::StringCchLengthW(sczSessionId, STRSAFE_MAX_CCH, reinterpret_cast<size_t*>(&cchSessionId));
        ExitOnFailure(hr, "Failed to get length of session id string.");
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, 0, sczTempFolder + cchTempFolder - cchSessionId, static_cast<DWORD>(cchSessionId), sczSessionId, static_cast<DWORD>(cchSessionId)))
+        if (cchTempFolder >= cchSessionId &&
+            CSTR_EQUAL == ::CompareStringOrdinal(sczTempFolder + cchTempFolder - cchSessionId, static_cast<DWORD>(cchSessionId), sczSessionId, static_cast<DWORD>(cchSessionId), FALSE))
        {
            cchTempFolder -= cchSessionId;
        }
diff --git a/src/burn/engine/manifest.cpp b/src/burn/engine/manifest.cpp
index 266d1987..b2680387 100644
--- a/src/burn/engine/manifest.cpp
+++ b/src/burn/engine/manifest.cpp
@@ -177,7 +177,7 @@ static void ValidateHarvestingAttributes(
    hr = XmlGetYesNoAttribute(pixeBundle, L"Win64", &fWin64);
    ExitOnRequiredXmlQueryFailure(hr, "Failed to get BurnManifest/@Win64 attribute.");
-    Assert(CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, sczEngineVersion, -1, wzVerMajorMinorBuild, -1));
+    Assert(CSTR_EQUAL == ::CompareStringOrdinal(sczEngineVersion, -1, wzVerMajorMinorBuild, -1, FALSE));
    Assert(BURN_PROTOCOL_VERSION == dwProtocolVersion);
diff --git a/src/burn/engine/msiengine.cpp b/src/burn/engine/msiengine.cpp
index d5268b17..a1379054 100644
--- a/src/burn/engine/msiengine.cpp
+++ b/src/burn/engine/msiengine.cpp
@@ -50,7 +50,9 @@ static void RegisterSourceDirectory(
    __in BURN_PACKAGE* pPackage,
    __in_z LPCWSTR wzCacheDirectory
    );
+static BOOL PackageHasAppliedPatch(
+    __in BURN_PACKAGE* pPackage
+    );
 // function definitions
@@ -523,7 +525,7 @@ extern "C" HRESULT MsiEngineDetectPackage(
            ExitOnFailure(hr, "Failed to enum related products.");
            // If we found ourselves, skip because saying that a package is related to itself is nonsensical.
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pPackage->Msi.sczProductCode, -1, wzProductCode, -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(pPackage->Msi.sczProductCode, -1, wzProductCode, -1, TRUE))
            {
                continue;
            }
@@ -631,7 +633,7 @@ extern "C" HRESULT MsiEngineDetectPackage(
                }
                // It can't be a downgrade if the upgrade codes aren't the same.
                else if (BOOTSTRAPPER_PACKAGE_STATE_ABSENT == pPackage->currentState &&
-                         pPackage->Msi.sczUpgradeCode && CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pPackage->Msi.sczUpgradeCode, -1, pRelatedMsi->sczUpgradeCode, -1))
+                         pPackage->Msi.sczUpgradeCode && CSTR_EQUAL == ::CompareStringOrdinal(pPackage->Msi.sczUpgradeCode, -1, pRelatedMsi->sczUpgradeCode, -1, TRUE))
                {
                    relatedMsiOperation = BOOTSTRAPPER_RELATED_OPERATION_DOWNGRADE;
                    pPackage->Msi.operation = BOOTSTRAPPER_RELATED_OPERATION_DOWNGRADE;
@@ -904,7 +906,22 @@ extern "C" HRESULT MsiEnginePlanCalculatePackage(
        else if ((BOOTSTRAPPER_REQUEST_STATE_ABSENT == pPackage->requested || BOOTSTRAPPER_REQUEST_STATE_CACHE == pPackage->requested) &&
                 !pPackage->fPermanent) // removing a package that should be removed.
        {
-            execute = BOOTSTRAPPER_PACKAGE_STATE_SUPERSEDED == pPackage->currentState ? BOOTSTRAPPER_ACTION_STATE_NONE : BOOTSTRAPPER_ACTION_STATE_UNINSTALL;
+            if (BOOTSTRAPPER_PACKAGE_STATE_SUPERSEDED == pPackage->currentState)
+            {
+                // If the package is superseded, check to see if there's a patch installed.
+                // A minor upgrade patch could be (usually is) the cause of the
+                // supersedence. In that case, we should ignore the supersedence that would
+                // normally prevent the uninstall. There is a gap in this logic: If a minor
+                // upgrade package were installed without a bundle, then a small update patch
+                // (which by definition doesn't change the version number) were installed,
+                // this check would allow the uninstall. If the minor upgrade were installed
+                // by a bundle, dependencies would keep the package installed.
+                execute = PackageHasAppliedPatch(pPackage) ? BOOTSTRAPPER_ACTION_STATE_UNINSTALL : BOOTSTRAPPER_ACTION_STATE_NONE;
+            }
+            else
+            {
+                execute = BOOTSTRAPPER_ACTION_STATE_UNINSTALL;
+            }
        }
        else if (BOOTSTRAPPER_REQUEST_STATE_FORCE_ABSENT == pPackage->requested)
        {
@@ -2141,7 +2158,7 @@ static HRESULT ConcatFeatureActionProperties(
    if (sczAddLocal)
    {
-        hr = StrAllocFormatted(&scz, L" ADDLOCAL=\"%s\"", sczAddLocal, 0);
+        hr = StrAllocFormatted(&scz, L" ADDLOCAL=\"%s\"", sczAddLocal);
        ExitOnFailure(hr, "Failed to format ADDLOCAL string.");
        hr = StrAllocConcatSecure(psczArguments, scz, 0);
@@ -2150,7 +2167,7 @@ static HRESULT ConcatFeatureActionProperties(
    if (sczAddSource)
    {
-        hr = StrAllocFormatted(&scz, L" ADDSOURCE=\"%s\"", sczAddSource, 0);
+        hr = StrAllocFormatted(&scz, L" ADDSOURCE=\"%s\"", sczAddSource);
        ExitOnFailure(hr, "Failed to format ADDSOURCE string.");
        hr = StrAllocConcatSecure(psczArguments, scz, 0);
@@ -2159,7 +2176,7 @@ static HRESULT ConcatFeatureActionProperties(
    if (sczAddDefault)
    {
-        hr = StrAllocFormatted(&scz, L" ADDDEFAULT=\"%s\"", sczAddDefault, 0);
+        hr = StrAllocFormatted(&scz, L" ADDDEFAULT=\"%s\"", sczAddDefault);
        ExitOnFailure(hr, "Failed to format ADDDEFAULT string.");
        hr = StrAllocConcatSecure(psczArguments, scz, 0);
@@ -2168,7 +2185,7 @@ static HRESULT ConcatFeatureActionProperties(
    if (sczReinstall)
    {
-        hr = StrAllocFormatted(&scz, L" REINSTALL=\"%s\"", sczReinstall, 0);
+        hr = StrAllocFormatted(&scz, L" REINSTALL=\"%s\"", sczReinstall);
        ExitOnFailure(hr, "Failed to format REINSTALL string.");
        hr = StrAllocConcatSecure(psczArguments, scz, 0);
@@ -2177,7 +2194,7 @@ static HRESULT ConcatFeatureActionProperties(
    if (sczAdvertise)
    {
-        hr = StrAllocFormatted(&scz, L" ADVERTISE=\"%s\"", sczAdvertise, 0);
+        hr = StrAllocFormatted(&scz, L" ADVERTISE=\"%s\"", sczAdvertise);
        ExitOnFailure(hr, "Failed to format ADVERTISE string.");
        hr = StrAllocConcatSecure(psczArguments, scz, 0);
@@ -2186,7 +2203,7 @@ static HRESULT ConcatFeatureActionProperties(
    if (sczRemove)
    {
-        hr = StrAllocFormatted(&scz, L" REMOVE=\"%s\"", sczRemove, 0);
+        hr = StrAllocFormatted(&scz, L" REMOVE=\"%s\"", sczRemove);
        ExitOnFailure(hr, "Failed to format REMOVE string.");
        hr = StrAllocConcatSecure(psczArguments, scz, 0);
@@ -2265,6 +2282,7 @@ LExit:
    ReleaseStr(sczMspPath);
    ReleaseStr(sczCachedDirectory);
    ReleaseStr(sczPatches);
    return hr;
 }
@@ -2289,6 +2307,47 @@ static void RegisterSourceDirectory(
 LExit:
    ReleaseStr(sczMsiDirectory);
+}
+static BOOL PackageHasAppliedPatch(
+    __in BURN_PACKAGE* pPackage
+)
+{
+    HRESULT hr = S_OK;
+    BOOL fPatched = FALSE;
+    UINT er = ERROR_SUCCESS;
+    DWORD iPatch = 0;
+    WCHAR wzPatchCode[MAX_GUID_CHARS + 1] = {};
+    WCHAR wzTransforms[MAX_PATH] = {};
+    DWORD cchTransforms = countof(wzTransforms);
+    WCHAR wzPatchState[2] = {};
+    DWORD cchPatchState = countof(wzPatchState);
+    for (;;)
+    {
+        er = ::MsiEnumPatchesW(pPackage->Msi.sczProductCode, iPatch, wzPatchCode, wzTransforms, &cchTransforms);
+        if (ERROR_NO_MORE_ITEMS == er)
+        {
+            ExitFunction();
+        }
+        ExitOnWin32Error(er, hr, "Failed to enumerate patches for package %ls, product code %ls.", pPackage->sczId, pPackage->Msi.sczProductCode);
+        er = ::MsiGetPatchInfoExW(wzPatchCode, pPackage->Msi.sczProductCode, NULL, pPackage->fPerMachine ? MSIINSTALLCONTEXT_MACHINE : MSIINSTALLCONTEXT_USERUNMANAGED
+            , INSTALLPROPERTY_PATCHSTATE, wzPatchState, &cchPatchState);
+        ExitOnWin32Error(er, hr, "Failed to get patch info for patch %ls.", wzPatchCode);
+        if ('1' == wzPatchState[0])
+        {
+            fPatched = TRUE;
+            ExitFunction();
+        }
+        ++iPatch;
+    }
+LExit:
+    return fPatched;
-    return;
 }
diff --git a/src/burn/engine/mspengine.cpp b/src/burn/engine/mspengine.cpp
index c057c06d..e8ef7fcb 100644
--- a/src/burn/engine/mspengine.cpp
+++ b/src/burn/engine/mspengine.cpp
@@ -771,7 +771,7 @@ extern "C" void MspEngineUpdateInstallRegistrationState(
        {
            pTargetProduct = pPackage->Msp.rgTargetProducts + j;
            if (pAction->mspTarget.fPerMachineTarget == (MSIINSTALLCONTEXT_MACHINE == pTargetProduct->context) &&
-                CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, 0, pAction->mspTarget.sczTargetProductCode, -1, pTargetProduct->wzTargetProductCode, -1))
+                CSTR_EQUAL == ::CompareStringOrdinal(pAction->mspTarget.sczTargetProductCode, -1, pTargetProduct->wzTargetProductCode, -1, FALSE))
            {
                break;
            }
@@ -1069,7 +1069,7 @@ static HRESULT DeterminePatchChainedTarget(
    {
        BURN_PACKAGE* pPackage = pPackages->rgPackages + iPackage;
-        if (BURN_PACKAGE_TYPE_MSI == pPackage->type && CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, 0, wzTargetProductCode, -1, pPackage->Msi.sczProductCode, -1))
+        if (BURN_PACKAGE_TYPE_MSI == pPackage->type && CSTR_EQUAL == ::CompareStringOrdinal(wzTargetProductCode, -1, pPackage->Msi.sczProductCode, -1, FALSE))
        {
            pTargetProduct->pChainedTargetPackage = pPackage;
@@ -1123,7 +1123,7 @@ static HRESULT PlanTargetProduct(
        if (BURN_EXECUTE_ACTION_TYPE_MSP_TARGET == pAction->type &&
            pAction->mspTarget.action == actionState &&
            pAction->mspTarget.fPerMachineTarget == (MSIINSTALLCONTEXT_MACHINE == pTargetProduct->context) &&
-            CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, 0, pAction->mspTarget.sczTargetProductCode, -1, pTargetProduct->wzTargetProductCode, -1))
+            CSTR_EQUAL == ::CompareStringOrdinal(pAction->mspTarget.sczTargetProductCode, -1, pTargetProduct->wzTargetProductCode, -1, FALSE))
        {
            dwInsertSequence = i;
            break;
diff --git a/src/burn/engine/msuengine.cpp b/src/burn/engine/msuengine.cpp
index 43f5f76c..d31691a5 100644
--- a/src/burn/engine/msuengine.cpp
+++ b/src/burn/engine/msuengine.cpp
@@ -313,6 +313,8 @@ LExit:
        SetServiceStartType(schWu, SERVICE_DISABLED);
    }
+    ReleaseServiceHandle(schWu);
    // Best effort to clear the execute package cache folder variable.
    VariableSetString(pVariables, BURN_BUNDLE_EXECUTE_PACKAGE_CACHE_FOLDER, NULL, TRUE, FALSE);
diff --git a/src/burn/engine/package.cpp b/src/burn/engine/package.cpp
index fe8af497..3bf676ba 100644
--- a/src/burn/engine/package.cpp
+++ b/src/burn/engine/package.cpp
@@ -123,15 +123,15 @@ extern "C" HRESULT PackagesParseFromXml(
        if (fFoundXml)
        {
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"remove", -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"remove", -1, FALSE))
            {
                pPackage->authoredCacheType = BOOTSTRAPPER_CACHE_TYPE_REMOVE;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"keep", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"keep", -1, FALSE))
            {
                pPackage->authoredCacheType = BOOTSTRAPPER_CACHE_TYPE_KEEP;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"force", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"force", -1, FALSE))
            {
                pPackage->authoredCacheType = BOOTSTRAPPER_CACHE_TYPE_FORCE;
            }
@@ -210,28 +210,28 @@ extern "C" HRESULT PackagesParseFromXml(
        }
        // read type specific attributes
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"BundlePackage", -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"BundlePackage", -1, FALSE))
        {
            pPackage->type = BURN_PACKAGE_TYPE_BUNDLE;
            hr = BundlePackageEngineParsePackageFromXml(pixnNode, pPackage); // TODO: Modularization
            ExitOnFailure(hr, "Failed to parse BUNDLE package.");
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"ExePackage", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"ExePackage", -1, FALSE))
        {
            pPackage->type = BURN_PACKAGE_TYPE_EXE;
            hr = ExeEngineParsePackageFromXml(pixnNode, pPackage); // TODO: Modularization
            ExitOnFailure(hr, "Failed to parse EXE package.");
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"MsiPackage", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"MsiPackage", -1, FALSE))
        {
            pPackage->type = BURN_PACKAGE_TYPE_MSI;
            hr = MsiEngineParsePackageFromXml(pixnNode, pPackage); // TODO: Modularization
            ExitOnFailure(hr, "Failed to parse MSI package.");
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"MspPackage", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"MspPackage", -1, FALSE))
        {
            pPackage->type = BURN_PACKAGE_TYPE_MSP;
@@ -240,7 +240,7 @@ extern "C" HRESULT PackagesParseFromXml(
            ++cMspPackages;
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"MsuPackage", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"MsuPackage", -1, FALSE))
        {
            pPackage->type = BURN_PACKAGE_TYPE_MSU;
@@ -315,7 +315,7 @@ extern "C" HRESULT PackagesParseFromXml(
                    {
                        for (DWORD k = 0; k < pMsiPackage->Msi.cSlipstreamMspPackages; ++k)
                        {
-                            if (pMsiPackage->Msi.rgsczSlipstreamMspPackageIds[k] && CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, pPackage->sczId, -1, pMsiPackage->Msi.rgsczSlipstreamMspPackageIds[k], -1))
+                            if (pMsiPackage->Msi.rgsczSlipstreamMspPackageIds[k] && CSTR_EQUAL == ::CompareStringOrdinal(pPackage->sczId, -1, pMsiPackage->Msi.rgsczSlipstreamMspPackageIds[k], -1, FALSE))
                            {
                                BURN_SLIPSTREAM_MSP* pSlipstreamMsp = pMsiPackage->Msi.rgSlipstreamMsps + k;
                                pSlipstreamMsp->pMspPackage = pPackage;
@@ -486,7 +486,7 @@ extern "C" HRESULT PackageFindById(
    {
        pPackage = &pPackages->rgPackages[i];
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, pPackage->sczId, -1, wzId, -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(pPackage->sczId, -1, wzId, -1, FALSE))
        {
            *ppPackage = pPackage;
            ExitFunction1(hr = S_OK);
@@ -508,7 +508,7 @@ extern "C" HRESULT PackageFindRelatedById(
 {
    HRESULT hr = S_OK;
    BURN_RELATED_BUNDLE* pRelatedBundle = NULL;
-    
    hr = RelatedBundleFindById(pRelatedBundles, wzId, &pRelatedBundle);
    *ppPackage = FAILED(hr) ? NULL : &pRelatedBundle->package;
@@ -551,7 +551,7 @@ extern "C" HRESULT PackageGetProperty(
    {
        const BURN_MSIPROPERTY* pProperty = &rgProperties[i];
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, 0, pProperty->sczId, -1, wzProperty, -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(pProperty->sczId, -1, wzProperty, -1, FALSE))
        {
            if (psczValue)
            {
@@ -580,7 +580,7 @@ extern "C" HRESULT PackageFindRollbackBoundaryById(
    {
        pRollbackBoundary = &pPackages->rgRollbackBoundaries[i];
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, pRollbackBoundary->sczId, -1, wzId, -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(pRollbackBoundary->sczId, -1, wzId, -1, FALSE))
        {
            *ppRollbackBoundary = pRollbackBoundary;
            ExitFunction1(hr = S_OK);
@@ -730,7 +730,7 @@ static HRESULT FindRollbackBoundaryById(
    {
        pRollbackBoundary = &pPackages->rgRollbackBoundaries[i];
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, pRollbackBoundary->sczId, -1, wzId, -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(pRollbackBoundary->sczId, -1, wzId, -1, FALSE))
        {
            *ppRollbackBoundary = pRollbackBoundary;
            ExitFunction1(hr = S_OK);
diff --git a/src/burn/engine/payload.cpp b/src/burn/engine/payload.cpp
index 270da6aa..a2649f97 100644
--- a/src/burn/engine/payload.cpp
+++ b/src/burn/engine/payload.cpp
@@ -80,11 +80,11 @@ extern "C" HRESULT PayloadsParseFromXml(
            hr = XmlGetAttributeEx(pixnNode, L"Packaging", &scz);
            ExitOnRequiredXmlQueryFailure(hr, "Failed to get @Packaging.");
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"embedded", -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"embedded", -1, FALSE))
            {
                pPayload->packaging = BURN_PAYLOAD_PACKAGING_EMBEDDED;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"external", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"external", -1, FALSE))
            {
                pPayload->packaging = BURN_PAYLOAD_PACKAGING_EXTERNAL;
            }
diff --git a/src/burn/engine/plan.cpp b/src/burn/engine/plan.cpp
index 7994dd32..edc09033 100644
--- a/src/burn/engine/plan.cpp
+++ b/src/burn/engine/plan.cpp
@@ -376,20 +376,6 @@ extern "C" HRESULT PlanDefaultPackageRequestState(
            break;
        }
    }
-    else if (BOOTSTRAPPER_RELATION_PATCH == relationType && BURN_PACKAGE_TYPE_MSP == packageType)
-    {
-        // For patch related bundles, only install a patch if currently absent during install, modify, or repair.
-        if (BOOTSTRAPPER_PACKAGE_STATE_ABSENT != currentState)
-        {
-            *pRequestState = BOOTSTRAPPER_REQUEST_STATE_NONE;
-        }
-        else if (BOOTSTRAPPER_ACTION_INSTALL == action ||
-                 BOOTSTRAPPER_ACTION_MODIFY == action ||
-                 BOOTSTRAPPER_ACTION_REPAIR == action)
-        {
-            *pRequestState = BOOTSTRAPPER_REQUEST_STATE_PRESENT;
-        }
-    }
    else // pick the best option for the action state and install condition.
    {
        hr = GetActionDefaultRequestState(action, currentState, &defaultRequestState);
@@ -397,12 +383,28 @@ extern "C" HRESULT PlanDefaultPackageRequestState(
        if (BOOTSTRAPPER_ACTION_UNINSTALL != action && BOOTSTRAPPER_ACTION_UNSAFE_UNINSTALL != action)
        {
+            // For patch related bundles, only install a patch if currently absent during install, modify, or repair.
+            if (BOOTSTRAPPER_RELATION_PATCH == relationType && BURN_PACKAGE_TYPE_MSP == packageType)
+            {
+                if (BOOTSTRAPPER_PACKAGE_STATE_ABSENT != currentState)
+                {
+                    defaultRequestState = BOOTSTRAPPER_REQUEST_STATE_NONE;
+                }
+                else if (BOOTSTRAPPER_ACTION_INSTALL == action ||
+                    BOOTSTRAPPER_ACTION_MODIFY == action ||
+                    BOOTSTRAPPER_ACTION_REPAIR == action)
+                {
+                    defaultRequestState = BOOTSTRAPPER_REQUEST_STATE_PRESENT;
+                }
+            }
            // If we're not doing an uninstall, use the install condition
            // to determine whether to use the default request state or make the package absent.
            if (BOOTSTRAPPER_PACKAGE_CONDITION_FALSE == installCondition)
            {
                defaultRequestState = BOOTSTRAPPER_REQUEST_STATE_ABSENT;
            }
            // Obsolete means the package is not on the machine and should not be installed,
            // *except* patches can be obsolete and present.
            // Superseded means the package is on the machine but not active, so only uninstall operations are allowed.
@@ -1540,7 +1542,7 @@ extern "C" HRESULT PlanRelatedBundlesComplete(
        if (fBundle && BOOTSTRAPPER_ACTION_STATE_NONE != packageAction)
        {
-            if (pPackage->cDependencyProviders)
+            if (pPackage && pPackage->cDependencyProviders)
            {
                // Bundles only support a single provider key.
                const BURN_DEPENDENCY_PROVIDER* pProvider = pPackage->rgDependencyProviders;
@@ -1554,7 +1556,7 @@ extern "C" HRESULT PlanRelatedBundlesComplete(
    for (DWORD i = 0; i < pRegistration->relatedBundles.cRelatedBundles; ++i)
    {
-        DWORD *pdwInsertIndex = NULL;
+        DWORD* pdwInsertIndex = NULL;
        BURN_RELATED_BUNDLE* pRelatedBundle = pRegistration->relatedBundles.rgpPlanSortedRelatedBundles[i];
        BOOL fDependent = BOOTSTRAPPER_RELATED_BUNDLE_PLAN_TYPE_DEPENDENT_ADDON == pRelatedBundle->planRelationType ||
                          BOOTSTRAPPER_RELATED_BUNDLE_PLAN_TYPE_DEPENDENT_PATCH == pRelatedBundle->planRelationType;
@@ -2013,6 +2015,7 @@ extern "C" HRESULT PlanRollbackBoundaryComplete(
    // Add checkpoints.
    hr = PlanExecuteCheckpoint(pPlan);
+    ExitOnFailure(hr, "Failed to append execute checkpoint for rollback boundary complete.");
    // Add complete rollback boundary to execute plan.
    hr = PlanAppendExecuteAction(pPlan, &pExecuteAction);
@@ -2948,9 +2951,9 @@ static void ExecuteActionLog(
    case BURN_EXECUTE_ACTION_TYPE_PACKAGE_DEPENDENCY:
        LogStringLine(PlanDumpLevel, "%ls action[%u]: PACKAGE_DEPENDENCY package id: %ls, bundle provider key: %ls", wzBase, iAction, pAction->packageDependency.pPackage->sczId, pAction->packageDependency.sczBundleProviderKey);
-        for (DWORD j = 0; j < pAction->packageProvider.pPackage->cDependencyProviders; ++j)
+        for (DWORD j = 0; j < pAction->packageDependency.pPackage->cDependencyProviders; ++j)
        {
-            const BURN_DEPENDENCY_PROVIDER* pProvider = pAction->packageProvider.pPackage->rgDependencyProviders + j;
+            const BURN_DEPENDENCY_PROVIDER* pProvider = pAction->packageDependency.pPackage->rgDependencyProviders + j;
            LogStringLine(PlanDumpLevel, "      Provider[%u]: key: %ls, action: %hs", j, pProvider->sczKey, LoggingDependencyActionToString(fRollback ? pProvider->dependentRollback : pProvider->dependentExecute));
        }
        break;
diff --git a/src/burn/engine/pseudobundle.cpp b/src/burn/engine/pseudobundle.cpp
index f0d67068..ff7f185c 100644
--- a/src/burn/engine/pseudobundle.cpp
+++ b/src/burn/engine/pseudobundle.cpp
@@ -127,8 +127,8 @@ extern "C" HRESULT PseudoBundleInitializePassthrough(
    ExitOnFailure(hr, "Failed to copy cache id for passthrough pseudo bundle.");
    // Log variables - best effort
-    StrAllocFormatted(&pPackage->sczLogPathVariable, L"WixBundleLog_%ls", pPackage->sczId);
+    StrAllocFormatted(&pPassthroughPackage->sczLogPathVariable, L"WixBundleLog_%ls", pPackage->sczId);
-    StrAllocFormatted(&pPackage->sczRollbackLogPathVariable, L"WixBundleRollbackLog_%ls", pPackage->sczId);
+    StrAllocFormatted(&pPassthroughPackage->sczRollbackLogPathVariable, L"WixBundleRollbackLog_%ls", pPackage->sczId);
    hr = CoreCreatePassthroughBundleCommandLine(&sczArguments, pInternalCommand, pCommand);
    ExitOnFailure(hr, "Failed to create command-line arguments.");
@@ -155,6 +155,8 @@ extern "C" HRESULT PseudoBundleInitializeUpdateBundle(
 {
    HRESULT hr = S_OK;
    BURN_PAYLOAD* pPayload = NULL;
+    BYTE* rgbHash = NULL;
+    DWORD cbHash = 0;
    // Initialize the single payload, and fill out all the necessary fields
    pPackage->payloads.rgItems = (BURN_PAYLOAD_GROUP_ITEM*)MemAlloc(sizeof(BURN_PAYLOAD_GROUP_ITEM), TRUE);
@@ -185,9 +187,6 @@ extern "C" HRESULT PseudoBundleInitializeUpdateBundle(
    if (wzHash && *wzHash)
    {
-        BYTE* rgbHash = NULL;
-        DWORD cbHash = 0;
        hr = StrAllocHexDecode(wzHash, &rgbHash, &cbHash);
        ExitOnFailure(hr, "Failed to decode hash string: %ls.", wzHash);
@@ -223,5 +222,7 @@ extern "C" HRESULT PseudoBundleInitializeUpdateBundle(
    ExitOnFailure(hr, "Failed to copy install arguments for update bundle package");
 LExit:
+    ReleaseStr(rgbHash);
    return hr;
 }
diff --git a/src/burn/engine/registration.cpp b/src/burn/engine/registration.cpp
index 85c006f7..9733e92c 100644
--- a/src/burn/engine/registration.cpp
+++ b/src/burn/engine/registration.cpp
@@ -223,15 +223,15 @@ extern "C" HRESULT RegistrationParseFromXml(
        if (fFoundXml)
        {
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"button", -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"button", -1, FALSE))
            {
                pRegistration->modify = BURN_REGISTRATION_MODIFY_DISABLE_BUTTON;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"yes", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"yes", -1, FALSE))
            {
                pRegistration->modify = BURN_REGISTRATION_MODIFY_DISABLE;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"no", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"no", -1, FALSE))
            {
                pRegistration->modify = BURN_REGISTRATION_MODIFY_ENABLED;
            }
@@ -808,13 +808,6 @@ extern "C" HRESULT RegistrationSessionBegin(
        ExitOnFailure(hr, "Failed to write software tags.");
    }
-    // Update registration.
-    if (pRegistration->update.fRegisterUpdate)
-    {
-        hr = WriteUpdateRegistration(pRegistration, pVariables);
-        ExitOnFailure(hr, "Failed to write update registration.");
-    }
    // Only set install date and initial estimated size here for the first time.
    // Estimated size will always get updated at the end of the session.
    if (fCreated)
@@ -904,6 +897,13 @@ extern "C" HRESULT RegistrationSessionEnd(
        hr = UpdateEstimatedSize(hkRegistration, qwEstimatedSize);
        ExitOnFailure(hr, "Failed to update estimated size.");
+        // Update registration.
+        if (pRegistration->update.fRegisterUpdate)
+        {
+            hr = WriteUpdateRegistration(pRegistration, pVariables);
+            ExitOnFailure(hr, "Failed to write update registration.");
+        }
    }
    // Update resume mode.
@@ -1512,7 +1512,7 @@ static HRESULT RemoveUpdateRegistration(
        hr = RegReadString(hkKey, L"PackageVersion", &sczPackageVersion);
        if (SUCCEEDED(hr))
        {
-            if (CSTR_EQUAL != ::CompareStringW(LOCALE_INVARIANT, 0, sczPackageVersion, -1, pRegistration->sczDisplayVersion, -1))
+            if (CSTR_EQUAL != ::CompareStringOrdinal(sczPackageVersion, -1, pRegistration->sczDisplayVersion, -1, FALSE))
            {
                fDeleteRegKey = FALSE;
            }
diff --git a/src/burn/engine/relatedbundle.cpp b/src/burn/engine/relatedbundle.cpp
index 938b24d7..c9aa7170 100644
--- a/src/burn/engine/relatedbundle.cpp
+++ b/src/burn/engine/relatedbundle.cpp
@@ -116,7 +116,7 @@ extern "C" HRESULT RelatedBundleFindById(
        pRelatedBundle = pRelatedBundles->rgRelatedBundles + i;
        pPackage = &pRelatedBundle->package;
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, pPackage->sczId, -1, wzId, -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(pPackage->sczId, -1, wzId, -1, FALSE))
        {
            *ppRelatedBundle = pRelatedBundle;
            ExitFunction1(hr = S_OK);
@@ -206,7 +206,7 @@ static __callback int __cdecl CompareRelatedBundlesDetect(
        VerCompareParsedVersions(pBundleLeft->pVersion, pBundleRight->pVersion, &ret);
        if (0 == ret)
        {
-            ret = ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, pBundleLeft->package.sczId, -1, pBundleRight->package.sczId, -1) - 2;
+            ret = ::CompareStringOrdinal(pBundleLeft->package.sczId, -1, pBundleRight->package.sczId, -1, TRUE) - 2;
        }
    }
@@ -249,7 +249,7 @@ static __callback int __cdecl CompareRelatedBundlesPlan(
        VerCompareParsedVersions(pBundleLeft->pVersion, pBundleRight->pVersion, &ret);
        if (0 == ret)
        {
-            ret = ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, pBundleLeft->package.sczId, -1, pBundleRight->package.sczId, -1) - 2;
+            ret = ::CompareStringOrdinal(pBundleLeft->package.sczId, -1, pBundleRight->package.sczId, -1, TRUE) - 2;
        }
    }
@@ -284,7 +284,7 @@ static HRESULT LoadIfRelatedBundle(
    BURN_RELATED_BUNDLE* pRelatedBundle = NULL;
    // If we found our bundle code, it's not a related bundle.
-    if (CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pBundle->wzBundleCode, -1, pRegistration->sczCode, -1))
+    if (CSTR_EQUAL == ::CompareStringOrdinal(pBundle->wzBundleCode, -1, pRegistration->sczCode, -1, TRUE))
    {
        ExitFunction1(hr = S_FALSE);
    }
diff --git a/src/burn/engine/search.cpp b/src/burn/engine/search.cpp
index a1b6b74a..a60215fe 100644
--- a/src/burn/engine/search.cpp
+++ b/src/burn/engine/search.cpp
@@ -106,7 +106,7 @@ extern "C" HRESULT SearchesParseFromXml(
        ExitOnOptionalXmlQueryFailure(hr, fXmlFound, "Failed to get @Condition.");
        // read type specific attributes
-        if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"DirectorySearch", -1))
+        if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"DirectorySearch", -1, FALSE))
        {
            pSearch->Type = BURN_SEARCH_TYPE_DIRECTORY;
@@ -118,11 +118,11 @@ extern "C" HRESULT SearchesParseFromXml(
            hr = XmlGetAttributeEx(pixnNode, L"Type", &scz);
            ExitOnRequiredXmlQueryFailure(hr, "Failed to get @Type.");
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"exists", -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"exists", -1, FALSE))
            {
                pSearch->DirectorySearch.Type = BURN_DIRECTORY_SEARCH_TYPE_EXISTS;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"path", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"path", -1, FALSE))
            {
                pSearch->DirectorySearch.Type = BURN_DIRECTORY_SEARCH_TYPE_PATH;
            }
@@ -131,7 +131,7 @@ extern "C" HRESULT SearchesParseFromXml(
                ExitWithRootFailure(hr, E_INVALIDARG, "Invalid value for @Type: %ls", scz);
            }
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"FileSearch", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"FileSearch", -1, FALSE))
        {
            pSearch->Type = BURN_SEARCH_TYPE_FILE;
@@ -147,15 +147,15 @@ extern "C" HRESULT SearchesParseFromXml(
            hr = XmlGetAttributeEx(pixnNode, L"Type", &scz);
            ExitOnRequiredXmlQueryFailure(hr, "Failed to get @Type.");
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"exists", -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"exists", -1, FALSE))
            {
                pSearch->FileSearch.Type = BURN_FILE_SEARCH_TYPE_EXISTS;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"version", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"version", -1, FALSE))
            {
                pSearch->FileSearch.Type = BURN_FILE_SEARCH_TYPE_VERSION;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"path", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"path", -1, FALSE))
            {
                pSearch->FileSearch.Type = BURN_FILE_SEARCH_TYPE_PATH;
            }
@@ -164,7 +164,7 @@ extern "C" HRESULT SearchesParseFromXml(
                ExitWithRootFailure(hr, E_INVALIDARG, "Invalid value for @Type: %ls", scz);
            }
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"RegistrySearch", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"RegistrySearch", -1, FALSE))
        {
            pSearch->Type = BURN_SEARCH_TYPE_REGISTRY;
@@ -172,19 +172,19 @@ extern "C" HRESULT SearchesParseFromXml(
            hr = XmlGetAttributeEx(pixnNode, L"Root", &scz);
            ExitOnRequiredXmlQueryFailure(hr, "Failed to get @Root.");
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"HKCR", -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"HKCR", -1, FALSE))
            {
                pSearch->RegistrySearch.hRoot = HKEY_CLASSES_ROOT;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"HKCU", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"HKCU", -1, FALSE))
            {
                pSearch->RegistrySearch.hRoot = HKEY_CURRENT_USER;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"HKLM", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"HKLM", -1, FALSE))
            {
                pSearch->RegistrySearch.hRoot = HKEY_LOCAL_MACHINE;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"HKU", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"HKU", -1, FALSE))
            {
                pSearch->RegistrySearch.hRoot = HKEY_USERS;
            }
@@ -208,11 +208,11 @@ extern "C" HRESULT SearchesParseFromXml(
            hr = XmlGetYesNoAttribute(pixnNode, L"Win64", &pSearch->RegistrySearch.fWin64);
            ExitOnOptionalXmlQueryFailure(hr, fXmlFound, "Failed to get Win64 attribute.");
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"exists", -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"exists", -1, FALSE))
            {
                pSearch->RegistrySearch.Type = BURN_REGISTRY_SEARCH_TYPE_EXISTS;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"value", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"value", -1, FALSE))
            {
                pSearch->RegistrySearch.Type = BURN_REGISTRY_SEARCH_TYPE_VALUE;
@@ -224,19 +224,19 @@ extern "C" HRESULT SearchesParseFromXml(
                hr = XmlGetAttributeEx(pixnNode, L"VariableType", &scz);
                ExitOnRequiredXmlQueryFailure(hr, "Failed to get @VariableType.");
-                if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"formatted", -1))
+                if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"formatted", -1, FALSE))
                {
                    pSearch->RegistrySearch.VariableType = BURN_VARIANT_TYPE_FORMATTED;
                }
-                else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"numeric", -1))
+                else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"numeric", -1, FALSE))
                {
                    pSearch->RegistrySearch.VariableType = BURN_VARIANT_TYPE_NUMERIC;
                }
-                else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"string", -1))
+                else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"string", -1, FALSE))
                {
                    pSearch->RegistrySearch.VariableType = BURN_VARIANT_TYPE_STRING;
                }
-                else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"version", -1))
+                else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"version", -1, FALSE))
                {
                    pSearch->RegistrySearch.VariableType = BURN_VARIANT_TYPE_VERSION;
                }
@@ -250,7 +250,7 @@ extern "C" HRESULT SearchesParseFromXml(
                ExitWithRootFailure(hr, E_INVALIDARG, "Invalid value for @Type: %ls", scz);
            }
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"MsiComponentSearch", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"MsiComponentSearch", -1, FALSE))
        {
            pSearch->Type = BURN_SEARCH_TYPE_MSI_COMPONENT;
@@ -266,15 +266,15 @@ extern "C" HRESULT SearchesParseFromXml(
            hr = XmlGetAttributeEx(pixnNode, L"Type", &scz);
            ExitOnRequiredXmlQueryFailure(hr, "Failed to get @Type.");
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"keyPath", -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"keyPath", -1, FALSE))
            {
                pSearch->MsiComponentSearch.Type = BURN_MSI_COMPONENT_SEARCH_TYPE_KEYPATH;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"state", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"state", -1, FALSE))
            {
                pSearch->MsiComponentSearch.Type = BURN_MSI_COMPONENT_SEARCH_TYPE_STATE;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"directory", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"directory", -1, FALSE))
            {
                pSearch->MsiComponentSearch.Type = BURN_MSI_COMPONENT_SEARCH_TYPE_DIRECTORY;
            }
@@ -283,7 +283,7 @@ extern "C" HRESULT SearchesParseFromXml(
                ExitWithRootFailure(hr, E_INVALIDARG, "Invalid value for @Type: %ls", scz);
            }
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"MsiProductSearch", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"MsiProductSearch", -1, FALSE))
        {
            pSearch->Type = BURN_SEARCH_TYPE_MSI_PRODUCT;
            pSearch->MsiProductSearch.GuidType = BURN_MSI_PRODUCT_SEARCH_GUID_TYPE_NONE;
@@ -318,28 +318,32 @@ extern "C" HRESULT SearchesParseFromXml(
            hr = XmlGetAttributeEx(pixnNode, L"Type", &scz);
            ExitOnRequiredXmlQueryFailure(hr, "Failed to get @Type.");
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"version", -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"version", -1, FALSE))
            {
                pSearch->MsiProductSearch.Type = BURN_MSI_PRODUCT_SEARCH_TYPE_VERSION;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"language", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"language", -1, FALSE))
            {
                pSearch->MsiProductSearch.Type = BURN_MSI_PRODUCT_SEARCH_TYPE_LANGUAGE;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"state", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"state", -1, FALSE))
            {
                pSearch->MsiProductSearch.Type = BURN_MSI_PRODUCT_SEARCH_TYPE_STATE;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"assignment", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"assignment", -1, FALSE))
            {
                pSearch->MsiProductSearch.Type = BURN_MSI_PRODUCT_SEARCH_TYPE_ASSIGNMENT;
            }
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"exists", -1, FALSE))
+            {
+                pSearch->MsiProductSearch.Type = BURN_MSI_PRODUCT_SEARCH_TYPE_EXISTS;
+            }
            else
            {
                ExitWithRootFailure(hr, E_INVALIDARG, "Invalid value for @Type: %ls", scz);
            }
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"ExtensionSearch", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"ExtensionSearch", -1, FALSE))
        {
            pSearch->Type = BURN_SEARCH_TYPE_EXTENSION;
@@ -350,7 +354,7 @@ extern "C" HRESULT SearchesParseFromXml(
            hr = BurnExtensionFindById(pBurnExtensions, scz, &pSearch->ExtensionSearch.pExtension);
            ExitOnRootFailure(hr, "Failed to find extension '%ls' for search '%ls'", scz, pSearch->sczKey);
        }
-        else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, bstrNodeName, -1, L"SetVariable", -1))
+        else if (CSTR_EQUAL == ::CompareStringOrdinal(bstrNodeName, -1, L"SetVariable", -1, FALSE))
        {
            pSearch->Type = BURN_SEARCH_TYPE_SET_VARIABLE;
@@ -367,19 +371,19 @@ extern "C" HRESULT SearchesParseFromXml(
                hr = XmlGetAttributeEx(pixnNode, L"Type", &scz);
                ExitOnRequiredXmlQueryFailure(hr, "Failed to get @Type.");
-                if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"formatted", -1))
+                if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"formatted", -1, FALSE))
                {
                    pSearch->SetVariable.targetType = BURN_VARIANT_TYPE_FORMATTED;
                }
-                else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"numeric", -1))
+                else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"numeric", -1, FALSE))
                {
                    pSearch->SetVariable.targetType = BURN_VARIANT_TYPE_NUMERIC;
                }
-                else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"string", -1))
+                else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"string", -1, FALSE))
                {
                    pSearch->SetVariable.targetType = BURN_VARIANT_TYPE_STRING;
                }
-                else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"version", -1))
+                else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"version", -1, FALSE))
                {
                    pSearch->SetVariable.targetType = BURN_VARIANT_TYPE_VERSION;
                }
@@ -1144,6 +1148,7 @@ static HRESULT MsiProductSearch(
    case BURN_MSI_PRODUCT_SEARCH_TYPE_LANGUAGE:
        wzProperty = INSTALLPROPERTY_LANGUAGE;
        break;
+    case BURN_MSI_PRODUCT_SEARCH_TYPE_EXISTS: __fallthrough;
    case BURN_MSI_PRODUCT_SEARCH_TYPE_STATE:
        wzProperty = INSTALLPROPERTY_PRODUCTSTATE;
        break;
@@ -1218,6 +1223,7 @@ static HRESULT MsiProductSearch(
        case BURN_MSI_PRODUCT_SEARCH_TYPE_LANGUAGE:
            // is supposed to remain empty
            break;
+        case BURN_MSI_PRODUCT_SEARCH_TYPE_EXISTS: __fallthrough;
        case BURN_MSI_PRODUCT_SEARCH_TYPE_STATE:
            value.Type = BURN_VARIANT_TYPE_NUMERIC;
            value.llValue = INSTALLSTATE_ABSENT;
@@ -1237,6 +1243,7 @@ static HRESULT MsiProductSearch(
    case BURN_MSI_PRODUCT_SEARCH_TYPE_LANGUAGE:
        type = BURN_VARIANT_TYPE_STRING;
        break;
+    case BURN_MSI_PRODUCT_SEARCH_TYPE_EXISTS: __fallthrough;
    case BURN_MSI_PRODUCT_SEARCH_TYPE_STATE: __fallthrough;
    case BURN_MSI_PRODUCT_SEARCH_TYPE_ASSIGNMENT:
        type = BURN_VARIANT_TYPE_NUMERIC;
@@ -1245,6 +1252,13 @@ static HRESULT MsiProductSearch(
    hr = BVariantChangeType(&value, type);
    ExitOnFailure(hr, "Failed to change value type.");
+    // When testing if a product exists, replace the value with a numeric "true" or "false"
+    // based on the calculated install state.
+    if (BURN_MSI_PRODUCT_SEARCH_TYPE_EXISTS == pSearch->MsiProductSearch.Type)
+    {
+        value.llValue = (value.llValue == INSTALLSTATE_ABSENT) ? 0 : 1;
+    }
    // Set variable.
    hr = VariableSetVariant(pVariables, pSearch->sczVariable, &value);
    ExitOnFailure(hr, "Failed to set variable.");
diff --git a/src/burn/engine/search.h b/src/burn/engine/search.h
index 341fe1aa..e70645c5 100644
--- a/src/burn/engine/search.h
+++ b/src/burn/engine/search.h
@@ -58,6 +58,7 @@ enum BURN_MSI_PRODUCT_SEARCH_TYPE
    BURN_MSI_PRODUCT_SEARCH_TYPE_LANGUAGE,
    BURN_MSI_PRODUCT_SEARCH_TYPE_STATE,
    BURN_MSI_PRODUCT_SEARCH_TYPE_ASSIGNMENT,
+    BURN_MSI_PRODUCT_SEARCH_TYPE_EXISTS,
 };
 enum BURN_MSI_PRODUCT_SEARCH_GUID_TYPE
diff --git a/src/burn/engine/splashscreen.cpp b/src/burn/engine/splashscreen.cpp
index 0bfa00aa..21ddfa98 100644
--- a/src/burn/engine/splashscreen.cpp
+++ b/src/burn/engine/splashscreen.cpp
@@ -371,6 +371,7 @@ static void OnEraseBkgnd(
    HDC hdc = reinterpret_cast<HDC>(wParam);
    HDC hdcMem = ::CreateCompatibleDC(hdc);
    HBITMAP hDefaultBitmap = static_cast<HBITMAP>(::SelectObject(hdcMem, pSplashScreen->hBitmap));
+    ::SetStretchBltMode(hdc, HALFTONE);
    ::StretchBlt(hdc, 0, 0, pSplashScreen->size.cx, pSplashScreen->size.cy, hdcMem, 0, 0, pSplashScreen->defaultDpiSize.cx, pSplashScreen->defaultDpiSize.cy, SRCCOPY);
    ::SelectObject(hdcMem, hDefaultBitmap);
    ::DeleteDC(hdcMem);
diff --git a/src/burn/engine/variable.cpp b/src/burn/engine/variable.cpp
index 9d0aec52..a795d76c 100644
--- a/src/burn/engine/variable.cpp
+++ b/src/burn/engine/variable.cpp
@@ -397,7 +397,7 @@ extern "C" HRESULT VariablesParseFromXml(
            hr = XmlGetAttributeEx(pixnNode, L"Type", &scz);
            ExitOnRequiredXmlQueryFailure(hr, "Failed to get @Type.");
-            if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"formatted", -1))
+            if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"formatted", -1, FALSE))
            {
                if (!fHidden)
                {
@@ -405,7 +405,7 @@ extern "C" HRESULT VariablesParseFromXml(
                }
                valueType = BURN_VARIANT_TYPE_FORMATTED;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"numeric", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"numeric", -1, FALSE))
            {
                if (!fHidden)
                {
@@ -413,7 +413,7 @@ extern "C" HRESULT VariablesParseFromXml(
                }
                valueType = BURN_VARIANT_TYPE_NUMERIC;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"string", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"string", -1, FALSE))
            {
                if (!fHidden)
                {
@@ -421,7 +421,7 @@ extern "C" HRESULT VariablesParseFromXml(
                }
                valueType = BURN_VARIANT_TYPE_STRING;
            }
-            else if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, scz, -1, L"version", -1))
+            else if (CSTR_EQUAL == ::CompareStringOrdinal(scz, -1, L"version", -1, FALSE))
            {
                if (!fHidden)
                {
@@ -1144,7 +1144,7 @@ extern "C" BOOL VariableIsHiddenCommandLine(
    {
        pVariable = pVariables->rgVariables + i;
-        if (pVariable->fHidden && CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, NORM_IGNORECASE, pVariable->sczName, -1, wzVariable, -1))
+        if (pVariable->fHidden && CSTR_EQUAL == ::CompareStringOrdinal(pVariable->sczName, -1, wzVariable, -1, TRUE))
        {
            fHidden = TRUE;
            break;
@@ -1556,7 +1556,7 @@ static HRESULT FindVariableIndexByName(
        DWORD iPosition = cRangeLength / 2;
        BURN_VARIABLE* pVariable = &pVariables->rgVariables[iRangeFirst + iPosition];
-        switch (::CompareStringW(LOCALE_INVARIANT, SORT_STRINGSORT, wzVariable, -1, pVariable->sczName, -1))
+        switch (::CompareStringOrdinal(wzVariable, -1, pVariable->sczName, -1, FALSE))
        {
        case CSTR_LESS_THAN:
            // restrict range to elements before the current
@@ -1591,7 +1591,7 @@ static HRESULT InsertUserVariable(
 {
    HRESULT hr = S_OK;
-    if (CSTR_EQUAL == ::CompareStringW(LOCALE_INVARIANT, 0, wzVariable, 3, L"Wix", 3))
+    if (CSTR_EQUAL == ::CompareStringOrdinal(wzVariable, 3, L"Wix", 3, FALSE))
    {
        ExitWithRootFailure(hr, E_INVALIDARG, "Attempted to insert variable with reserved prefix: %ls", wzVariable);
    }
diff --git a/src/burn/engine/variant.cpp b/src/burn/engine/variant.cpp
index 2267ee7b..3fc02aa8 100644
--- a/src/burn/engine/variant.cpp
+++ b/src/burn/engine/variant.cpp
@@ -10,6 +10,9 @@ static HRESULT GetVersionInternal(
    __in BOOL fSilent,
    __out VERUTIL_VERSION** ppValue
    );
+static void FreeVariantValue(
+    __in BURN_VARIANT* pVariant
+    );
 // function definitions
@@ -17,12 +20,7 @@ extern "C" void BVariantUninitialize(
    __in BURN_VARIANT* pVariant
    )
 {
-    if (BURN_VARIANT_TYPE_FORMATTED == pVariant->Type ||
+    FreeVariantValue(pVariant);
-        BURN_VARIANT_TYPE_STRING == pVariant->Type)
-    {
-        StrSecureZeroFreeString(pVariant->sczValue);
-    }
-    SecureZeroMemory(pVariant, sizeof(BURN_VARIANT));
 }
 extern "C" HRESULT BVariantGetNumeric(
@@ -164,12 +162,8 @@ extern "C" HRESULT BVariantSetNumeric(
 {
    HRESULT hr = S_OK;
-    if (BURN_VARIANT_TYPE_FORMATTED == pVariant->Type ||
+    FreeVariantValue(pVariant);
-        BURN_VARIANT_TYPE_STRING == pVariant->Type)
-    {
-        StrSecureZeroFreeString(pVariant->sczValue);
-    }
-    memset(pVariant, 0, sizeof(BURN_VARIANT));
    pVariant->llValue = llValue;
    pVariant->Type = BURN_VARIANT_TYPE_NUMERIC;
@@ -194,7 +188,7 @@ extern "C" HRESULT BVariantSetString(
        if (BURN_VARIANT_TYPE_FORMATTED != pVariant->Type &&
            BURN_VARIANT_TYPE_STRING != pVariant->Type)
        {
-            memset(pVariant, 0, sizeof(BURN_VARIANT));
+            FreeVariantValue(pVariant);
        }
        hr = StrAllocStringSecure(&pVariant->sczValue, wzValue, cchValue);
@@ -220,12 +214,8 @@ extern "C" HRESULT BVariantSetVersion(
    }
    else // assign the value.
    {
-        if (BURN_VARIANT_TYPE_FORMATTED == pVariant->Type ||
+        FreeVariantValue(pVariant);
-            BURN_VARIANT_TYPE_STRING == pVariant->Type)
-        {
-            StrSecureZeroFreeString(pVariant->sczValue);
-        }
-        memset(pVariant, 0, sizeof(BURN_VARIANT));
        hr = VerCopyVersion(pValue, &pVariant->pValue);
        pVariant->Type = BURN_VARIANT_TYPE_VERSION;
    }
@@ -319,3 +309,20 @@ extern "C" HRESULT BVariantChangeType(
 LExit:
    return hr;
 }
+static void FreeVariantValue(
+    __in BURN_VARIANT* pVariant
+    )
+{
+    if ((BURN_VARIANT_TYPE_FORMATTED == pVariant->Type || BURN_VARIANT_TYPE_STRING == pVariant->Type) && 
+        pVariant->sczValue)
+    {
+        StrSecureZeroFreeString(pVariant->sczValue);
+    }
+    else if (BURN_VARIANT_TYPE_VERSION == pVariant->Type && pVariant->pValue)
+    {
+        VerFreeVersion(pVariant->pValue);
+    }
+    SecureZeroMemory(pVariant, sizeof(BURN_VARIANT));
+}
diff --git a/src/burn/stub/WixToolset.Burn.props b/src/burn/stub/WixToolset.Burn.props
index 38cd333e..debcffd0 100644
--- a/src/burn/stub/WixToolset.Burn.props
+++ b/src/burn/stub/WixToolset.Burn.props
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
-<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup>
    <BurnExes Include="$(MSBuildThisFileDirectory)..\tools\**\burn.exe" />
    <None Include="@(BurnExes)">
diff --git a/src/burn/stub/precomp.h b/src/burn/stub/precomp.h
index 46239a6c..b72cd012 100644
--- a/src/burn/stub/precomp.h
+++ b/src/burn/stub/precomp.h
@@ -13,6 +13,7 @@
 #include <strutil.h>
 #include <fileutil.h>
 #include <pathutil.h>
+#include <polcutil.h>
 #include <logutil.h>
 #include "engine.h"
diff --git a/src/burn/stub/stub.cpp b/src/burn/stub/stub.cpp
index d8cee9f1..ea5d88f0 100644
--- a/src/burn/stub/stub.cpp
+++ b/src/burn/stub/stub.cpp
@@ -34,6 +34,8 @@ int WINAPI wWinMain(
        L"feclient.dll", // unsafely loaded by DecryptFile().
    };
+    AppSetDefaultProcessMitigationPolicy(POLICY_BURN_REGISTRY_PATH);
    // Best effort attempt to get our file handle as soon as possible.
    hr = PathForCurrentProcess(&sczPath, NULL);
    if (SUCCEEDED(hr))
diff --git a/src/burn/stub/stub.vcxproj b/src/burn/stub/stub.vcxproj
index d07b8da7..54825b95 100644
--- a/src/burn/stub/stub.vcxproj
+++ b/src/burn/stub/stub.vcxproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
-<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup Label="ProjectConfigurations">
    <ProjectConfiguration Include="Debug|Win32">
      <Configuration>Debug</Configuration>
diff --git a/src/burn/test/BurnUnitTest/ApprovedExeTest.cpp b/src/burn/test/BurnUnitTest/ApprovedExeTest.cpp
new file mode 100644
index 00000000..da51f1f8
--- /dev/null
+++ b/src/burn/test/BurnUnitTest/ApprovedExeTest.cpp
@@ -0,0 +1,312 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+#include "precomp.h"
+namespace Microsoft
+{
+namespace Tools
+{
+namespace WindowsInstallerXml
+{
+namespace Test
+{
+namespace Bootstrapper
+{
+    using namespace System;
+    using namespace System::IO;
+    using namespace Xunit;
+    public ref class ApprovedExeTest : BurnUnitTest
+    {
+    public:
+        ApprovedExeTest(BurnTestFixture^ fixture) : BurnUnitTest(fixture)
+        {
+        }
+        [Fact]
+        void ApprovedExesVerifyPFilesTest()
+        {
+            HRESULT hr = S_OK;
+            BURN_CACHE cache = { };
+            BURN_ENGINE_COMMAND internalCommand = { };
+            BURN_VARIABLES variables = { };
+            LPWSTR scz = NULL;
+            LPWSTR scz2 = NULL;
+            try
+            {
+                hr = VariableInitialize(&variables);
+                NativeAssert::Succeeded(hr, L"Failed to initialize variables.");
+                hr = CacheInitialize(&cache, &internalCommand);
+                NativeAssert::Succeeded(hr, "Failed to initialize cache.");
+                hr = VariableGetString(&variables, L"ProgramFilesFolder", &scz);
+                NativeAssert::Succeeded(hr, "Failed to get variable ProgramFilesFolder.");
+                hr = PathConcat(scz, L"a.exe", &scz2);
+                NativeAssert::Succeeded(hr, "Failed to combine paths");
+                hr = ApprovedExesVerifySecureLocation(&cache, &variables, scz2, 0, NULL);
+                NativeAssert::Succeeded(hr, "Failed to test secure location under ProgramFilesFolder");
+                Assert::True((hr == S_OK), "Path under ProgramFilesFolder was expected to be safe");
+            }
+            finally
+            {
+                ReleaseStr(internalCommand.sczEngineWorkingDirectory);
+                ReleaseStr(scz);
+                ReleaseStr(scz2);
+                CacheUninitialize(&cache);
+                VariablesUninitialize(&variables);
+            }
+        }
+        [Fact]
+        void ApprovedExesVerifyPFilesWithRelativeTest()
+        {
+            HRESULT hr = S_OK;
+            BURN_CACHE cache = { };
+            BURN_ENGINE_COMMAND internalCommand = { };
+            BURN_VARIABLES variables = { };
+            LPWSTR scz = NULL;
+            LPWSTR scz2 = NULL;
+            try
+            {
+                hr = VariableInitialize(&variables);
+                NativeAssert::Succeeded(hr, L"Failed to initialize variables.");
+                hr = CacheInitialize(&cache, &internalCommand);
+                NativeAssert::Succeeded(hr, "Failed to initialize cache.");
+                cache.fPerMachineCacheRootVerified = TRUE;
+                cache.fOriginalPerMachineCacheRootVerified = TRUE;
+                hr = VariableGetString(&variables, L"ProgramFilesFolder", &scz);
+                NativeAssert::Succeeded(hr, "Failed to get variable ProgramFilesFolder.");
+                hr = PathConcat(scz, L"..\\a.exe", &scz2);
+                NativeAssert::Succeeded(hr, "Failed to combine paths");
+                hr = ApprovedExesVerifySecureLocation(&cache, &variables, scz2, 0, NULL);
+                NativeAssert::Succeeded(hr, "Failed to test secure location under ProgramFilesFolder");
+                Assert::True((hr == S_FALSE), "Path pretending to be under ProgramFilesFolder was expected to be unsafe");
+            }
+            finally
+            {
+                ReleaseStr(internalCommand.sczEngineWorkingDirectory);
+                ReleaseStr(scz);
+                ReleaseStr(scz2);
+                CacheUninitialize(&cache);
+                VariablesUninitialize(&variables);
+            }
+        }
+        [Fact]
+        void ApprovedExesVerifyPFiles64Test()
+        {
+            HRESULT hr = S_OK;
+            BURN_CACHE cache = { };
+            BURN_ENGINE_COMMAND internalCommand = { };
+            BURN_VARIABLES variables = { };
+            LPWSTR scz = NULL;
+            LPWSTR scz2 = NULL;
+            try
+            {
+                hr = VariableInitialize(&variables);
+                NativeAssert::Succeeded(hr, L"Failed to initialize variables.");
+                hr = CacheInitialize(&cache, &internalCommand);
+                NativeAssert::Succeeded(hr, "Failed to initialize cache.");
+                hr = VariableGetString(&variables, L"ProgramFiles64Folder", &scz);
+                NativeAssert::Succeeded(hr, "Failed to get variable ProgramFiles64Folder.");
+                hr = PathConcat(scz, L"a.exe", &scz2);
+                NativeAssert::Succeeded(hr, "Failed to combine paths");
+                hr = ApprovedExesVerifySecureLocation(&cache, &variables, scz2, 0, NULL);
+                NativeAssert::Succeeded(hr, "Failed to test secure location under ProgramFiles64Folder");
+                Assert::True((hr == S_OK), "Path under ProgramFiles64Folder was expected to be safe");
+            }
+            finally
+            {
+                ReleaseStr(internalCommand.sczEngineWorkingDirectory);
+                ReleaseStr(scz);
+                ReleaseStr(scz2);
+                CacheUninitialize(&cache);
+                VariablesUninitialize(&variables);
+            }
+        }
+        [Fact]
+        void ApprovedExesVerifySys64FolderTest()
+        {
+            HRESULT hr = S_OK;
+            BURN_CACHE cache = { };
+            BURN_ENGINE_COMMAND internalCommand = { };
+            BURN_VARIABLES variables = { };
+            LPWSTR scz = NULL;
+            LPWSTR scz2 = NULL;
+            try
+            {
+                hr = VariableInitialize(&variables);
+                NativeAssert::Succeeded(hr, L"Failed to initialize variables.");
+                hr = CacheInitialize(&cache, &internalCommand);
+                NativeAssert::Succeeded(hr, "Failed to initialize cache.");
+                cache.fPerMachineCacheRootVerified = TRUE;
+                cache.fOriginalPerMachineCacheRootVerified = TRUE;
+                hr = VariableGetString(&variables, L"System64Folder", &scz);
+                NativeAssert::Succeeded(hr, "Failed to get variable System64Folder.");
+                hr = PathConcat(scz, L"a.exe", &scz2);
+                NativeAssert::Succeeded(hr, "Failed to combine paths");
+                hr = ApprovedExesVerifySecureLocation(&cache, &variables, scz2, 0, NULL);
+                NativeAssert::Succeeded(hr, "Failed to test secure location under System64Folder");
+                Assert::True((hr == S_FALSE), "Path under System64Folder was expected to be unsafe");
+            }
+            finally
+            {
+                ReleaseStr(internalCommand.sczEngineWorkingDirectory);
+                ReleaseStr(scz);
+                ReleaseStr(scz2);
+                CacheUninitialize(&cache);
+                VariablesUninitialize(&variables);
+            }
+        }
+        [Fact]
+        void ApprovedExesVerifySys64Rundll32UnsafeTest()
+        {
+            HRESULT hr = S_OK;
+            BURN_CACHE cache = { };
+            BURN_ENGINE_COMMAND internalCommand = { };
+            BURN_VARIABLES variables = { };
+            LPWSTR scz = NULL;
+            LPWSTR scz2 = NULL;
+            LPWSTR szArgs = NULL;
+            try
+            {
+                hr = VariableInitialize(&variables);
+                NativeAssert::Succeeded(hr, L"Failed to initialize variables.");
+                hr = CacheInitialize(&cache, &internalCommand);
+                NativeAssert::Succeeded(hr, "Failed to initialize cache.");
+                cache.fPerMachineCacheRootVerified = TRUE;
+                cache.fOriginalPerMachineCacheRootVerified = TRUE;
+                hr = VariableGetString(&variables, L"System64Folder", &scz);
+                NativeAssert::Succeeded(hr, "Failed to get variable System64Folder.");
+                hr = PathConcat(scz, L"rundll32.exe", &scz2);
+                NativeAssert::Succeeded(hr, "Failed to combine paths");
+                hr = ApprovedExesVerifySecureLocation(&cache, &variables, scz2, 1, const_cast<LPCWSTR*>(&scz2));
+                NativeAssert::Succeeded(hr, "Failed to test secure location under System64Folder");
+                Assert::True((hr == S_FALSE), "Path under System64Folder was expected to be unsafe for rundll32 target");
+            }
+            finally
+            {
+                ReleaseStr(internalCommand.sczEngineWorkingDirectory);
+                ReleaseStr(scz);
+                ReleaseStr(scz2);
+                ReleaseStr(szArgs);
+                CacheUninitialize(&cache);
+                VariablesUninitialize(&variables);
+            }
+        }
+        [Fact]
+        void ApprovedExesVerifySys64Rundll32SafeTest()
+        {
+            HRESULT hr = S_OK;
+            BURN_CACHE cache = { };
+            BURN_ENGINE_COMMAND internalCommand = { };
+            BURN_VARIABLES variables = { };
+            LPWSTR scz = NULL;
+            LPWSTR scz2 = NULL;
+            LPWSTR scz3 = NULL;
+            try
+            {
+                hr = VariableInitialize(&variables);
+                NativeAssert::Succeeded(hr, L"Failed to initialize variables.");
+                hr = CacheInitialize(&cache, &internalCommand);
+                NativeAssert::Succeeded(hr, "Failed to initialize cache.");
+                cache.fPerMachineCacheRootVerified = TRUE;
+                cache.fOriginalPerMachineCacheRootVerified = TRUE;
+                // System64Folder
+                hr = VariableGetString(&variables, L"System64Folder", &scz);
+                NativeAssert::Succeeded(hr, "Failed to get variable System64Folder.");
+                hr = PathConcat(scz, L"rundll32.exe", &scz2);
+                NativeAssert::Succeeded(hr, "Failed to combine paths");
+                hr = VariableGetString(&variables, L"ProgramFiles64Folder", &scz);
+                NativeAssert::Succeeded(hr, "Failed to get variable ProgramFiles64Folder.");
+                hr = PathConcat(scz, L"a.dll", &scz3);
+                NativeAssert::Succeeded(hr, "Failed to combine paths");
+                hr = ApprovedExesVerifySecureLocation(&cache, &variables, scz2, 1, const_cast<LPCWSTR*>(&scz3));
+                NativeAssert::Succeeded(hr, "Failed to test secure location under ProgramFiles64Folder for System64Folder/rundll32 target");
+                Assert::True((hr == S_OK), "Path under ProgramFiles64Folder was expected to be safe for System64Folder/rundll32 target");
+                hr = PathConcat(scz, L"a.dll,somthing else", &scz3);
+                NativeAssert::Succeeded(hr, "Failed to combine paths");
+                hr = ApprovedExesVerifySecureLocation(&cache, &variables, scz2, 1, const_cast<LPCWSTR*>(&scz3));
+                NativeAssert::Succeeded(hr, "Failed to test secure location under ProgramFiles64Folder for rundll32 target");
+                Assert::True((hr == S_OK), "Path under ProgramFiles64Folder was expected to be safe for System64Folder/rundll32 target");
+                // SystemFolder
+                hr = VariableGetString(&variables, L"SystemFolder", &scz);
+                NativeAssert::Succeeded(hr, "Failed to get variable System64Folder.");
+                hr = PathConcat(scz, L"rundll32.exe", &scz2);
+                NativeAssert::Succeeded(hr, "Failed to combine paths");
+                hr = ApprovedExesVerifySecureLocation(&cache, &variables, scz2, 1, const_cast<LPCWSTR*>(&scz3));
+                NativeAssert::Succeeded(hr, "Failed to test secure location under ProgramFiles64Folder for SystemFolder/rundll32 target");
+                Assert::True((hr == S_OK), "Path under ProgramFiles64Folder was expected to be safe for SystemFolder/rundll32 target");
+                // Sysnative
+                hr = PathSystemWindowsSubdirectory(L"SysNative\\", &scz);
+                NativeAssert::Succeeded(hr, "Failed to get SysNative Folder.");
+                hr = PathConcat(scz, L"rundll32.exe", &scz2);
+                NativeAssert::Succeeded(hr, "Failed to combine paths");
+                hr = ApprovedExesVerifySecureLocation(&cache, &variables, scz2, 1, const_cast<LPCWSTR*>(&scz3));
+                NativeAssert::Succeeded(hr, "Failed to test secure location under ProgramFiles64Folder for Sysnative/rundll32 target");
+                Assert::True((hr == S_OK), "Path under ProgramFiles64Folder was expected to be safe for Sysnative/rundll32 target");
+            }
+            finally
+            {
+                ReleaseStr(internalCommand.sczEngineWorkingDirectory);
+                ReleaseStr(scz);
+                ReleaseStr(scz2);
+                ReleaseStr(scz3);
+                CacheUninitialize(&cache);
+                VariablesUninitialize(&variables);
+            }
+        }
+    };
+}
+}
+}
+}
+}
diff --git a/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj b/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj
index 331d237b..9704efa5 100644
--- a/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj
+++ b/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
-<Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <Import Project="..\..\..\internal\WixInternal.TestSupport.Native\build\WixInternal.TestSupport.Native.props" />
  <ItemGroup Label="ProjectConfigurations">
@@ -45,6 +45,7 @@
  <ItemGroup>
    <ClCompile Include="AssemblyInfo.cpp" />
+    <ClCompile Include="ApprovedExeTest.cpp" />
    <ClCompile Include="CacheTest.cpp" />
    <ClCompile Include="ElevationTest.cpp" />
    <ClCompile Include="EmbeddedTest.cpp" />
diff --git a/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj.filters b/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj.filters
index 82725436..aac5ab8b 100644
--- a/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj.filters
+++ b/src/burn/test/BurnUnitTest/BurnUnitTest.vcxproj.filters
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <ItemGroup>
    <Filter Include="Source Files">
      <UniqueIdentifier>{4FC737F1-C7A5-4376-A066-2A32D752A2FF}</UniqueIdentifier>
@@ -66,6 +66,9 @@
    <ClCompile Include="VariantTest.cpp">
      <Filter>Source Files</Filter>
    </ClCompile>
+    <ClCompile Include="ApprovedExeTest.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
  </ItemGroup>
  <ItemGroup>
    <ClInclude Include="BurnTestException.h">
@@ -95,4 +98,4 @@
      <Filter>Resource Files</Filter>
    </ResourceCompile>
  </ItemGroup>
-</Project>
-\ No newline at end of file
+</Project>
diff --git a/src/burn/test/BurnUnitTest/PlanTest.cpp b/src/burn/test/BurnUnitTest/PlanTest.cpp
index e426cb09..e2850a62 100644
--- a/src/burn/test/BurnUnitTest/PlanTest.cpp
+++ b/src/burn/test/BurnUnitTest/PlanTest.cpp
@@ -2990,6 +2990,18 @@ namespace Bootstrapper
            ValidateNonPermanentPackageExpectedStates(&pEngineState->packages.rgPackages[1], L"PackageA", BURN_PACKAGE_REGISTRATION_STATE_PRESENT, BURN_PACKAGE_REGISTRATION_STATE_PRESENT);
        }
+        [Fact]
+        void ValidateCacheVariables()
+        {
+            BURN_ENGINE_STATE engineState = { };
+            BURN_ENGINE_STATE* pEngineState = &engineState;
+            InitializeEngineStateForCorePlan(wzSlipstreamModifiedManifestFileName, pEngineState);
+            Assert::EndsWith(gcnew String(L".exe"), VariableGetStringHelper(&pEngineState->variables, BURN_BUNDLE_SOURCE_PROCESS_PATH));
+            Assert::EndsWith(gcnew String(L"\\"), VariableGetStringHelper(&pEngineState->variables, BURN_BUNDLE_SOURCE_PROCESS_FOLDER));
+        }
    private:
        // This doesn't initialize everything, just enough for CorePlan to work.
        void InitializeEngineStateForCorePlan(LPCWSTR wzManifestFileName, BURN_ENGINE_STATE* pEngineState)
@@ -3149,12 +3161,12 @@ namespace Bootstrapper
            if (pDependencies->fSelfDependent || pDependencies->fActiveParent)
            {
-                if (pDependencies->fActiveParent && CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pDependencies->wzActiveParent, -1, wzId, -1))
+                if (pDependencies->fActiveParent && CSTR_EQUAL == ::CompareStringOrdinal(pDependencies->wzActiveParent, -1, wzId, -1, TRUE))
                {
                    pRegistration->fParentRegisteredAsDependent = TRUE;
                }
-                if (pDependencies->fSelfDependent && CSTR_EQUAL == ::CompareStringW(LOCALE_NEUTRAL, NORM_IGNORECASE, pDependencies->wzSelfDependent, -1, wzId, -1))
+                if (pDependencies->fSelfDependent && CSTR_EQUAL == ::CompareStringOrdinal(pDependencies->wzSelfDependent, -1, wzId, -1, TRUE))
                {
                    pRegistration->fSelfRegisteredAsDependent = TRUE;
                }
diff --git a/src/burn/test/BurnUnitTest/SearchTest.cpp b/src/burn/test/BurnUnitTest/SearchTest.cpp
index a8e397c2..e3c714cb 100644
--- a/src/burn/test/BurnUnitTest/SearchTest.cpp
+++ b/src/burn/test/BurnUnitTest/SearchTest.cpp
@@ -410,6 +410,8 @@ namespace Bootstrapper
                    L"    <MsiProductSearch Id='Search4' Type='state' ProductCode='{600D0000-0000-0000-0000-000000000000}' Variable='Variable4' />"
                    L"    <MsiProductSearch Id='Search5' Type='assignment' ProductCode='{600D0000-0000-0000-0000-000000000000}' Variable='Variable5' />"
                    L"    <MsiProductSearch Id='Search6' Type='version' ProductCode='{600D0000-1000-0000-0000-000000000000}' Variable='Variable6' />"
+                    L"    <MsiProductSearch Id='Search7' Type='exists' ProductCode='{600D0000-0000-0000-0000-000000000000}' Variable='Variable7' />"
+                    L"    <MsiProductSearch Id='Search8' Type='exists' ProductCode='{BAD00000-0000-0000-0000-000000000000}' Variable='Variable8' />"
                    L"</Bundle>";
                // load XML document
@@ -429,6 +431,8 @@ namespace Bootstrapper
                Assert::Equal(5ll, VariableGetNumericHelper(&variables, L"Variable4"));
                Assert::Equal(1ll, VariableGetNumericHelper(&variables, L"Variable5"));
                Assert::Equal<String^>(gcnew String(L"1.0.0.0"), VariableGetVersionHelper(&variables, L"Variable6"));
+                Assert::Equal(1ll, VariableGetNumericHelper(&variables, L"Variable7"));
+                Assert::Equal(0ll, VariableGetNumericHelper(&variables, L"Variable8"));
            }
            finally
            {
diff --git a/src/burn/test/BurnUnitTest/precomp.h b/src/burn/test/BurnUnitTest/precomp.h
index f07f5968..ec6fb7d1 100644
--- a/src/burn/test/BurnUnitTest/precomp.h
+++ b/src/burn/test/BurnUnitTest/precomp.h
@@ -74,6 +74,7 @@
 #include "splashscreen.h"
 #include "detect.h"
 #include "externalengine.h"
+#include "approvedexe.h"
 #include "engine.version.h"