Here\'s what I\'ve done so far on my x64 OS:
After spending a while to get this to work (for me accepted answer didn't work, for me it's just half solution) i did following:
Sadly, you must have visual studio (i installed express edition 2013 for DESKTOP)
Installed python 2.7.3 (you don't have to set any environment variables)
Run cmd as administrator and go to you project root (where is you package.json file)
First run: npm config set python C:\Python27\python.exe
Then: npm install -msvs_version=2013
The trick is in command npm config set python ...path_to_python_exe...
which will be provided by npm to dependency which needs python i guess. I don't know why setting python as env variable is not enough.