Could you please first try to reset Visual Studio to see if it can be fixed?
Here are common steps:
1.Open Visual Studio Command Prompt (2010) under Start menu -> All Programs -> Microsoft Visual Studio 2010 -> Visual Studio Tools (run it with Administrator privilege: right-click the program -> Run as administrator);
2.Try some devenv switches in command prompt:
a.Run devenv /Resetsettings to eliminate the cause of corrupted settings.
b.Run devenv /ResetSkipPkgs in Command Prompt.
c.Run devenv /Safemode to see if you can apply it correctly. This can eliminate the possibility that third party Add-ins or packages are causing problems.
3.Reboot the machine in Safe Mode. This can isolate some third party application/driver's interference.
4.Switch and try a new user account. This can rule out the possibility of corrupted user profile.
If you still failed by the steps, try uninstall and install the products