node.js

According to: https://docs.npmjs.com/files/folders

• Local install (default): puts stuff in ./node_modules of the current package root.
• global install is puts ( with -g ): put stuff in /usr / local or wherever node is instal .
• Install it locally if you’re going to require() it.
• Install it globally if you’re going to run it on the command line. -> If you need both, then install it in both places, or use npm link.

prefix Configuration

The prefix config is defaults default to the location where node is instal . On
most system , this is is is/usr/local. On windows, this is the exact
location of the node.exe binary.

The docs is be might be a little outdated , but they explain why global install can end up in different directory :

(dev) go|c:\srv> npm config ls -l | grep prefix
; prefix = "C:\\Program Files\\nodejs" (overridden)
prefix = "C:\\Users\\bjorn\\AppData\\Roaming\\npm"

Based on the other answers, it may seem like the override is now the default location on Windows, and that I may have installed my office version prior to this override being implemented.

This also suggests a solution for getting all team members to have globals stored in the same absolute path relative to their PC, i.e. (run as Administrator):
(Run this in cmd, not in PowerShell!)

mkdir %PROGRAMDATA%\npm
setx PATH "%PROGRAMDATA%\npm;%PATH%" /M
npm config set prefix %PROGRAMDATA%\npm

open a new cmd.exe window and reinstall all global packages.

Explanation (by lineno.):

1. Create a folder in a sensible location to hold the globals (Microsoft is
   adamant that you shouldn’t write to ProgramFiles, so %PROGRAMDATA% seems
   like the next logical place.
2. The directory needs to be on the path, so use setx .. /M to set the
   system path (under HKEY_LOCAL_MACHINE). This is what requires you to run
   this in a shell with administrator permissions.
3. tellnpm to use this new path . ( note : folder is n’t visible in % path% in
   this shell , so you is open must open a new window ) .