diff --git a/src/OSSupport/File.cpp b/src/OSSupport/File.cpp
index 2194c46ee..cb6031da6 100644
--- a/src/OSSupport/File.cpp
+++ b/src/OSSupport/File.cpp
@@ -298,7 +298,7 @@ bool cFile::Rename(const AString & a_OrigFileName, const AString & a_NewFileName
 bool cFile::Copy(const AString & a_SrcFileName, const AString & a_DstFileName)
 {
 	#ifdef _WIN32
-		return (CopyFile(a_SrcFileName.c_str(), a_DstFileName.c_str(), true) != 0);
+		return (CopyFileA(a_SrcFileName.c_str(), a_DstFileName.c_str(), true) != 0);
 	#else
 		// Other OSs don't have a direct CopyFile equivalent, do it the harder way:
 		std::ifstream src(a_SrcFileName.c_str(), std::ios::binary);
@@ -322,7 +322,7 @@ bool cFile::Copy(const AString & a_SrcFileName, const AString & a_DstFileName)
 bool cFile::IsFolder(const AString & a_Path)
 {
 	#ifdef _WIN32
-		DWORD FileAttrib = GetFileAttributes(a_Path.c_str());
+		DWORD FileAttrib = GetFileAttributesA(a_Path.c_str());
 		return ((FileAttrib != INVALID_FILE_ATTRIBUTES) && ((FileAttrib & FILE_ATTRIBUTE_DIRECTORY) != 0));
 	#else
 		struct stat st;
@@ -337,7 +337,7 @@ bool cFile::IsFolder(const AString & a_Path)
 bool cFile::IsFile(const AString & a_Path)
 {
 	#ifdef _WIN32
-		DWORD FileAttrib = GetFileAttributes(a_Path.c_str());
+		DWORD FileAttrib = GetFileAttributesA(a_Path.c_str());
 		return ((FileAttrib != INVALID_FILE_ATTRIBUTES) && ((FileAttrib & (FILE_ATTRIBUTE_DIRECTORY | FILE_ATTRIBUTE_DEVICE)) == 0));
 	#else
 		struct stat st;
@@ -366,7 +366,7 @@ int cFile::GetSize(const AString & a_FileName)
 bool cFile::CreateFolder(const AString & a_FolderPath)
 {
 	#ifdef _WIN32
-		return (CreateDirectory(a_FolderPath.c_str(), NULL) != 0);
+		return (CreateDirectoryA(a_FolderPath.c_str(), NULL) != 0);
 	#else
 		return (mkdir(a_FolderPath.c_str(), S_IRWXU | S_IRWXG | S_IRWXO) == 0);
 	#endif
@@ -396,13 +396,13 @@ AStringVector cFile::GetFolderContents(const AString & a_Folder)
 	// Find all files / folders:
 	FileFilter.append("*.*");
 	HANDLE hFind;
-	WIN32_FIND_DATA FindFileData;
-	if ((hFind = FindFirstFile(FileFilter.c_str(), &FindFileData)) != INVALID_HANDLE_VALUE)
+	WIN32_FIND_DATAA FindFileData;
+	if ((hFind = FindFirstFileA(FileFilter.c_str(), &FindFileData)) != INVALID_HANDLE_VALUE)
 	{
 		do
 		{
 			AllFiles.push_back(FindFileData.cFileName);
-		} while (FindNextFile(hFind, &FindFileData));
+		} while (FindNextFileA(hFind, &FindFileData));
 		FindClose(hFind);
 	}
 	
diff --git a/src/OSSupport/IsThread.h b/src/OSSupport/IsThread.h
index c20fc3e7e..5de5f31c4 100644
--- a/src/OSSupport/IsThread.h
+++ b/src/OSSupport/IsThread.h
@@ -69,7 +69,7 @@ protected:
 		static DWORD __stdcall thrExecute(LPVOID a_Param)
 		{
 			// Create a window so that the thread can be identified by 3rd party tools:
-			HWND IdentificationWnd = CreateWindow("STATIC", ((cIsThread *)a_Param)->m_ThreadName.c_str(), 0, 0, 0, 0, WS_OVERLAPPED, NULL, NULL, NULL, NULL);
+			HWND IdentificationWnd = CreateWindowA("STATIC", ((cIsThread *)a_Param)->m_ThreadName.c_str(), 0, 0, 0, 0, WS_OVERLAPPED, NULL, NULL, NULL, NULL);
 			
 			// Run the thread:
 			((cIsThread *)a_Param)->Execute();