Errors Creating WCF Service Contract Interface

Tech-Archive recommends: Fix windows errors by optimizing your registry



I am "Walking Through" the VB Team's walkthrough of WCF support in VS2008.
In the IService interface the <ServiceContract()> indicates an error "Type 'ServiceContract' is not defined" and both <OperationContract()> are indicate "Type 'OperationContract' is not defined.

Any help?