1 files changed, 25 insertions, 2 deletions

diff --git a/CPP/Windows/FileSystem.cpp b/CPP/Windows/FileSystem.cpp
index 6a262d9..d11f02e 100644
--- a/CPP/Windows/FileSystem.cpp
+++ b/CPP/Windows/FileSystem.cpp
@@ -71,6 +71,12 @@ UINT MyGetDriveType(CFSTR pathName)
   }
 }
 
+#if !defined(Z7_WIN32_WINNT_MIN) || Z7_WIN32_WINNT_MIN < 0x0400
+// GetDiskFreeSpaceEx requires Windows95-OSR2, NT4
+#define Z7_USE_DYN_GetDiskFreeSpaceEx
+#endif
+
+#ifdef Z7_USE_DYN_GetDiskFreeSpaceEx
 typedef BOOL (WINAPI * Func_GetDiskFreeSpaceExA)(
   LPCSTR lpDirectoryName,                  // directory name
   PULARGE_INTEGER lpFreeBytesAvailable,    // bytes available to caller
@@ -84,6 +90,7 @@ typedef BOOL (WINAPI * Func_GetDiskFreeSpaceExW)(
   PULARGE_INTEGER lpTotalNumberOfBytes,    // bytes on disk
   PULARGE_INTEGER lpTotalNumberOfFreeBytes // free bytes on disk
 );
+#endif
 
 bool MyGetDiskFreeSpace(CFSTR rootPath, UInt64 &clusterSize, UInt64 &totalSize, UInt64 &freeSize)
 {
@@ -92,14 +99,22 @@ bool MyGetDiskFreeSpace(CFSTR rootPath, UInt64 &clusterSize, UInt64 &totalSize,
   #ifndef _UNICODE
   if (!g_IsNT)
   {
+#ifdef Z7_USE_DYN_GetDiskFreeSpaceEx
     const
     Func_GetDiskFreeSpaceExA f = Z7_GET_PROC_ADDRESS(
     Func_GetDiskFreeSpaceExA, GetModuleHandle(TEXT("kernel32.dll")),
         "GetDiskFreeSpaceExA");
     if (f)
+#endif
     {
       ULARGE_INTEGER freeBytesToCaller2, totalSize2, freeSize2;
-      sizeIsDetected = BOOLToBool(f(fs2fas(rootPath), &freeBytesToCaller2, &totalSize2, &freeSize2));
+      sizeIsDetected = BOOLToBool(
+#ifdef Z7_USE_DYN_GetDiskFreeSpaceEx
+        f
+#else
+        GetDiskFreeSpaceExA
+#endif
+          (fs2fas(rootPath), &freeBytesToCaller2, &totalSize2, &freeSize2));
       totalSize = totalSize2.QuadPart;
       freeSize = freeSize2.QuadPart;
     }
@@ -109,14 +124,22 @@ bool MyGetDiskFreeSpace(CFSTR rootPath, UInt64 &clusterSize, UInt64 &totalSize,
   else
   #endif
   {
+#ifdef Z7_USE_DYN_GetDiskFreeSpaceEx
     const
     Func_GetDiskFreeSpaceExW f = Z7_GET_PROC_ADDRESS(
     Func_GetDiskFreeSpaceExW, GetModuleHandle(TEXT("kernel32.dll")),
         "GetDiskFreeSpaceExW");
     if (f)
+#endif
     {
       ULARGE_INTEGER freeBytesToCaller2, totalSize2, freeSize2;
-      sizeIsDetected = BOOLToBool(f(fs2us(rootPath), &freeBytesToCaller2, &totalSize2, &freeSize2));
+      sizeIsDetected = BOOLToBool(
+#ifdef Z7_USE_DYN_GetDiskFreeSpaceEx
+        f
+#else
+        GetDiskFreeSpaceExW
+#endif
+          (fs2us(rootPath), &freeBytesToCaller2, &totalSize2, &freeSize2));
       totalSize = totalSize2.QuadPart;
       freeSize = freeSize2.QuadPart;
     }