Describes a registry search. Extensibility point in the WiX XML Schema. Schema extensions can register additional elements at this point in the schema. Overrides the default registry to search. The value `always64` will force the search to look in the 64-bit registry even when building for 32-bit. Simliarly, the value `always32` will force the search to look in the 32-bit registry even when building for 64-bit. The default value is `default` where the search will look in the same registry as the bitness of the package. Registry root hive to search under. HKEY_LOCAL_MACHINE HKEY_CURRENT_USER HKEY_CLASSES_ROOT HKEY_USERS Key to search for. Optional value to search for under the given Key. Whether to expand any environment variables in REG_SZ, REG_EXPAND_SZ, or REG_MULTI_SZ values. Rather than saving the matching registry value into the variable, a RegistrySearch can save an attribute of the matching entry instead. Saves true if a matching registry entry is found; false otherwise. Saves the value of the registry key in the variable. This is the default. Extensibility point in the WiX XML Schema. Schema extensions can register additional attributes at this point in the schema.