You must install IIS before installing .NET Framework 4. If you installed IIS after installing .NET Framework 4, you must register ASP.NET 4.0 with IIS. Open a Command prompt window by using the Run As Administrator option and then run the following command:
Update: Installation of the web console stuffs requires that ISAPI and CGI Restrictions in IIS be enabled for ASP.NET 4. To enable this, select the web server in IIS, and then double-click ISAPI and CGI Restrictions.
Select ASP.NET v4.0.30319, and then click Allow.