A hotfix rollup package is available for Windows Communication Foundation (WCF) in the Microsoft .NET Framework 3.0
Service Pack 2 (SP2) and in the Microsoft .NET Framework 4. The hotfix rollup package resolves issues that are described in the following Microsoft Knowledge Base (KB) articles:
FIX: Smsvchost.exe for the WCF service stops responding when you run a .NET Framework 4-based WCF service
FIX: Smsvchost.exe may crash when the Net.Tcp Port Sharing Service is used by a .NET Framework 4-based WCF service
Files labelled Windows6.1-KB2504602-xxx.msu apply to .Net 3.0 SP2 on Win7 RTM/WS2K8 R2 RTM.
Files labelled Windows6.1-KB2504602-v2-xxx.msu apply to .Net 3.0 SP2 on Win7 SP1/WS2K8 R2 SP1.