System.Web.WebPages version conflict

Error 5 Assembly 'System.Web.Helpers, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' uses 'System.Web.WebPages, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' which has a higher version than referenced assembly 'System.Web.WebPages, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' c:\Program Files (x86)\Microsoft ASP.NET\ASP.NET Web Pages\v2.0\Assemblies\System.Web.Helpers.dll MvcEnrollmentSystem


Since VS2010 installed or or express for web installed, I need to rename the two DLL to get it to compile and run