Tips : WCF Service not working on IIS 7.0
I was hosting my WCF services built on .NET 4.0 in IIS 7. It failed with the error System.TypeLoadException: Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. I tried the aspnet_regiis –iru and Bingo it worked. Hope this helps someone. Cheers!!!