If you want to get a copy of C# Language Specifications after you installed the VS.

C#4.0 Under Folder(VS2010):

C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC#\Specifications\1033

C#5.0 Under Folder(VS 2012 or VS2013):

C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC#\Specifications\1033