Running Vista and IIS7.0 can be painful at times. I deployed a simple WCF service then started receive HTTP 500 errors when browsing on the svc. Basically even though WCF is installed on Vista byu default the WCF HTTP Activations are disabled.
1. Open Control Panel
2. Go to Programs and Features
3. Pick Turn Windows Features on or off / Install
4. Under Microsoft .NET Framework 3.0 enable Windows Communication Foundation HTTP Activation and Windows Communication Foundation Non-HTTP Activation