We had a fresh install of Windows 2008 and Visual Studio 2010 on a developers machine that was getting this error when trying to access a MVC 2.0 .Net 4.0 website hosted locally on IIS7. Various fixes talk about making sure there is a default document, and also about turning on directory browsing, but neither of those work. (MVC 2.0 does not need a default document specified).
The issue was that .Net framework 4.0 had not installed correctly, so here is what you need to do to fix it.
1.) Run a command prompt as Administrator.
2.) Copy and paste the following text “C:WindowsMicrosoft.NETFramework64v4.0.30319aspnet_regiis.exe -i”
This is assuming that you have already installed MVC 2.0 And .Net Framework 4.0 , but not in the correct order.