How to debug:
1. see the error messages: "It is possible that a handler mapping is missing", "The feature you are trying to use may not be installed".
2. check handler mappings in IIS7 to see whether there is svc type. I did not find svc.
3. start optionalfeatures.exe to see whether WCF activation is enabled or not.
4. enabled WCF activation, then you can see svc appears in handler mappings.
5. 404.3 error goes away.