Why is System.Web.Mvc not listed in Add References?
In VS Express 2012 I couldn't find System.Web.Mvc in the "assemblies" tab, but after a bit of searching I found out that I need to look into "assemblies\extensions" tab rather than the default "assemblies\framework" tab.
Best way is to use NuGet package manager.
Just update the below MVC package and it should work.
I had the same issue and wasn't able to locate the System.Web.MVC reference assembly.
Finally found out and it was located inside the following location.
Note if your VS was installed in C: (Sometimes the MVC.dll is not in the default location which everybody talk about, i mean the "Reference Assemblies" folder located in the C: drive.)
if its not there, it should definitely be in here:
\Program Files (x86)\Microsoft ASP.NET\ASP.NET MVC 2\Assemblies\System.Web.Mvc.dll
So add the dll through navigating or the browse tab in the add reference menu.