Could not open Visual Studio 2013 for project C:/UnrealEngine4_Full/UE4.sln

I reinstall and did set the environment varible in windows 7 64bit to :
value : C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE

When i right click on some object in the class viewer and chose " open c++ header " nothing happens .

The message above pops only if i click on : file => Open visual studio .

I took this : VS110COMNTOOLS from tutorial that shows how to configure VS 2012 And i’v changed it into this VS120COMNTOOLS .
Cus 2013 is version 12 and still nothing .

Please post this on the AnswerHub.