Problem in running .net framework 4.0 website on iis 7.0

Question

Hey I got problem in running .NET framework 4.0 website on IIS7.0. the error I got is like:

HTTP Error 404.2 - Not Found \

Answer 1

In our case the solution to this problem did not involve the "ISAPI and CGI Restrictions" settings. The error started occuring after operations staff had upgraded the server to .NET 4.5 by accident, then downgraded to .NET 4.0 again. This caused some of the IIS websites to forget their respective correct application pools, and it caused some of the application pools to switch from .NET Framework 4.0 to 2.0. Changing these settings back fixed the problem.