[IIS] HTTP Error 404 in IIS 6.0

Error message 1
HTTP Error 404 - File Not Found

Error message 2
HTTP Error 404- File or Directory not found

Resolution:
1. Open IIS Manager, expand the master server node (that is, the Servername node), and then select the Web service extensions node.
2. In the right pane of IIS Manager, right-click the extension that you want to enable. In this example, this is Active Server Pages.
3. Click to select the Allow check box.

Please refer to http://support.microsoft.com/kb/315122