NPM is a Node Package Manager, and it's included in NodeJS installation package
It's good to update NPM in order to tackle some windows related symptoms, like too deep folder structures that some node packages use
There's a powershell script by MS that's an easy way to update NPM:
https://github.com/felixrieseberg/npm-windows-upgrade
You may need to alter the execution policy first
Set-ExecutionPolicy Unrestricted -Scope CurrentUser -Force
npm install -g npm-windows-upgrade
npm-windows-upgrade
Then run these commands
gyp ERR! stack Error: Python executable "python" is v3.5.0, which is not supported by gyp.
gyp ERR! stack You can pass the --python switch to point to Python >= v2.5.0 & < 3.0.0.