.Net 4.5 System dlls are missing after installing

问题:

I am working on MVC3 project in Visual studio 2012 targeting 4.5. Everything was right until I installed Windows8 SDK for Developing Apps for windows8 last night.After restarting Computer, All MVC3 projects have missing dlls.If reference to 4.0 version it just fine but again missing classes and I have changed targeting .Net version to 4.0 which I do not want at the moment.

This picture is showing all missing dlls.I tried to find in C:\Program Files (x86)\Reference Assemblies/Microsoft... but I could not find any 4.5 missing dll. OS: Windows 7

Update:

Now I have found 4.5 dlls in C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETCore\v4.5 but problem is for every Visual studio Project template.There is aslo another problem, System.Linq I have refrenced but Using System.Linq does not recognize this namespace.Can anybody suggest me tool or fix /update patch ?

Update 2: Visual studio removal and re installation didn't help ,it is still showing warning errors on dlls.