Looks like MSVS 11.0 Beta spoiled a MSVS 10.0 installation

Question

I ran into compilation problems with my MSVS 10 after installing MSVS 11Beta. Now, when I compile my C# Projects in MSVS 10 (Projects created in MSVS 10; Target framework: 3.5),

Answer 1

A similar questin was asked on the MSDN forums. Did you reboot after installing VS11?

http://social.msdn.microsoft.com/Forums/en-US/msbuild/thread/7d955d96-ff73-47d3-8830-85ea321eb4ab