If you are like me and use nmake and the command line to build C/C++ programs using Microsoft's tools, here is a trick to do that from within emacs. The following function opens a shell window in emacs that runs a shell with the compiler toolbox for building 64bit applications using the x86 executables that Visual Studio 2013 (express) ships. Changing x86_amd64 to other options selects other toolchains, such as 32 bits (x86), arm (arm), etc.
(defun vs2013-amd-shell () "Run `shell' with VC variables as the shell." (interactive) (let ((explicit-shell-file-name "cmd")) (progn (shell "*vc-shell*") (let ((b (get-buffer "*vc-shell*"))) (pop-to-buffer b) (end-of-buffer) (insert "call \"c:\\Program Files (x86)\\Microsoft Visual Studio 12.0\\VC\\vcvarsall.bat\" x86_amd64") (execute-kbd-macro "\C-m")))))