"C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\bin\vcvars32.bat"
"C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\vcvarsall.bat" x86
"C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\vcvarsall.bat" x86_amd64
scons
(Scons will automatically find CL.exe, and setup compilation for 64 bit.)