I\'m not 100% sure, but I believe I installed node v5 from the windows installer on both my home and office PCs.
On my home PC global installs happen under %APPDATA%
If you're just trying to find out where npm is installing your global module (the title of this thread), look at the output when running npm install -g sample_module
$ npm install -g sample_module C:\Users\user\AppData\Roaming\npm\sample_module -> C:\Users\user\AppData\Roaming\npm\node_modules\sample_module\bin\sample_module.js + sample_module@5.1.0 updated 1 package in 2.821s