In NetBeans using Java I can open java.lang.String class and I see that class source code. If I try to open System.String class in VisualStudio I see methods signatures only. 
Is it possible to install VisualStudio plug-in or something like that to open mscorlib classes source code pressing F12?

Thanks for your answers.
I've found the best solution for me: <http://visualstudiogallery.msdn.microsoft.com/95789cdb-08f9-4dae-9b2f-fc45a452ad77>