Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089

Solution :

start-> Run--> c:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -iru


use of -iru option

-ir	Installs and registers ASP.NET 4. This option is the same as the -i option except that this option does not change the CLR version that is associated with any existing application pools.
-  iru	If ASP.NET is not currently registered with IIS, performs the tasks described for -i. If a previous version of ASP.NET is already registered with IIS, this option performs the tasks described for -ir.