Compiler not found for VC Express 2013

I can’t use any C++ template or add new classes to open projects.
When selecting a C++ template as a base for a new project, I get a message that no compiler could be found and that VS 2013 has to be installed.

I have installed VS Express 2013 (VC++ included), but UE doesn’t seem to find it.
I saw a similar question being asked, where it was mentioned that UE looks for a certain reg-key.

Can someone tell me what that regkey is for VC++ Express 2013? I have tried to repair my VS installation, but that didn’t help…

Nevermind, found the answer via the forum.
If anyone else is experiencing the same problem, this is the solution:

Find the environment variable VS120COMNTOOLS and make sure it points to the correct location.
In my case it pointed to the standard installation folder in program files, but I had installed VS2013 Express to my D:.