What is this error (extension configuration) in IIS web server?

When I start my website on local IIS server (on Windows 7) .. I get this error message

HTTP Error 404.3 - Not Found
The page you are requesting cannot be served because of the extension configuration. If the page is a script, add a handler. If the file should be downloaded, add a MIME map.

Detailed Error Information
Module StaticFileModule
Notification ExecuteRequestHandler
Handler StaticFile
Error Code 0x80070032
Requested URL http://localhost:80/Default.aspx
Physical Path D:\مشروع الويب\comstorFinal\Default.aspx
Logon Method Anonymous
Logon User Anonymous

Looks like you don't have IIS7's ASP feature installed.

To install it: Start -> Run -> appwiz.cpl -> Turn Windows features on or off -> Internet Information Services -> World Wide Web Services -> Application Development Features -> ASP (check it and then click OK)