Hi,

From your SS I see that you are using Powershell, I'm guessing that most others are using the regular windows CMD shell.

So, I found this

http://stackoverflow.com/questions/19569990/npm-install-doesnt-work-in-windows-powershell

It might be worth giving that a try or even switching out to using the regular windows CMD prompt (I think node installs one and you'll find it as a shortcut).