Hi, I've developed an application in VS 2005 and I'm trying to test it in defferent 'clean' environments (meaning that only the OS has been installed) without contaming those environments with additional files in their system folders ('\Windows\system32' and '\Windows\WinSxS'). Here is how I have it: I run everything on the same machine. I'm developing under XP Pro (located on the F:\ drive) and I want to test the application on a 'clean' XP Pro (other language, located on the C:\ drive) and also a 'clean' Vista (located on the H:\ drive). This way I don't need to move my application, which is located separately on the D:\ drive, around. When I reboot XP on C:\ and I try to execute my application I get the error: "This application has failed to start because the application configuration is incorrect". This is caused by missing files (manifest... DLLs... MFC... CRT... etc. etc.) Now I've found a description of how to fix those files locally in the application folder: "How to: Deploy using XCopy" in "http://msdn2.microsoft.com/en-us/library/ms235291(VS.80).aspx". I did as they suggested in the second example "Deploying Visual C++ library DLLs as private assemblies": I did copy the Microsoft.VC80.CRT and Microsoft.VC80.MFC folders from %PROGDIR%\Microsoft Visual Studio 8\VC\Redist\x86 to the application folder. According to what stated in the description it should be enough for a 32-bit release. However it does not work, I receive the same error message as before. I also tried by copying the contained files (DLLs and manifest) rather the folders to the application folder, but without success. Can somebody help me to understand what is missing or wrong? Thanks in advance ElCarso