Could not load file or assembly 'System.Web.Mvc'

If you inherit old sitecore site version 6.5 or version 7.1 you are more likely to get a error that iis is complaining about finding System.Web.Mvc assembly.

<add assembly="System.Web.Mvc, Version=, Culture=neutral,PublicKeyToken=31BF3856AD364E35" />

You can download MVC 4 dlls from following link and install it on your local machine 

 I recommend to add required dlls later to solution and then set your dll to copy local.