If you are getting an error message with the phrase LockClrVersion could not be located in the dynamic link library mscoree.dll it is probably because you don't have the correct .net framework loaded. For the newer versions of C#/VB/etc.express (Visual Studio 8.0), you'll need to load the v2.0 .net framework.
If you're trying to execute Visual Studio from a location that isn't associated with your machine's installation, you'll probably move the error to some other error--at which point, a reinstall of vs will be your best bet. 