How do I see which version of MVC is installed?

C:\Program Files (x86)\Microsoft ASP.NET Inside this folder will be all versions of MVC that you have installed. This is for Win 7.

Look under Control Panel > Add/Remove Programs

Simply looking in the Program Files(x86) isn't enough. If you've installed MVC5 for instance via NuGet, then you won't see a MVC5 folder under that folder. In my opinion, the most effective way of knowing which version of MVC you are using is to go to your VS project and look at the references under your main web application. Then find "System.Web.Mvc", right click, then click properties. You will see the version as a property. I tried to post an image of this but it won't allow me to do that; oh well, sorry I couldn't.