How can I tell which version of MVC (i.e. MVC 2 Beta, MVC 2 RC) is installed on my machine?
The ASP.NET programs folder is the best place to look as it will show the versions in folders. To note though, if you installed Visual Studio 2012, then it installed both versions MVC3 and MVC4.
Try the MvcDiagnostics tool, which is available as a nuget package
As pointed out in this answer it is useful if you want to know what version of MVC your site is running.