In your IIS Manager:

  1. In the server node, select the ISAPI and CGI Restrictions option

  2. Enable the aspnet_isapi.dll for your version of .NET

  3. In the sites note, navigate to the site and select the Handler Mappings option

  4. Actions > Add Script Mapping

  5. Set:

    1. Request path: *

    2. Executable: path to the aspnet_isapi.dll that you enabled earlier

  6. Click the request restrictions button and clear the "Invoke handler only if request..." option.

  7. Ok