I have several dll files in the root of my system partition on a 64-bit Windows 2008 system. I will list them: msdia80.dll mfc70.dll mfc70u.dll msvci70.dll msvcp70.dll msvcr70.dll When searching on msdia80.dll, I found the following support article: http://support.microsoft.com/kb/927665 The article leads me to believe this is some incompatibility between old software and new 64-bit systems. In other words, Visual C++ 2005 wasn't designed with Windows 2008 64-bit in mind. Anyhow, the article provides a workaround which works great and gets my msdia80.dll file back where it should be. My question is whether there are similar workarounds for the other mentioned files? What are the correct paths to the files listed above, and is it as simple as running regsvr32 and registering those DLLs in their proper place?