Windows 8.1 installation disc for a friend

I have 8.1. For future reinstallation, I downloaded and burned an ISO from here: http://windows.microsoft.com/en-us/w...-refresh-media

What I want to know is if this will work for a friend's computer and I can just use his Windows 8 product key to activate it, or is this installation media tied to my product key?

Edit: Probably should have posted this at eight forums. My bad.

Yes you can use that media on his PC and Yes you can use his windows 8 key..
As long as the media edition matches the installation key (Pro edition - Pro key) (Core edition - Core Key)