I'm building a computer soon and found a site that sells games and windows 8.1 cd-keys at a discount for charity. What I plan to do is buy the CD-Key from this site and use it to download an ISO on my laptop then make that ISO into a bootable USB stick and put it in the new computer then install windows 8.1. My question is, is this possible? To download windows 8.1 with just a cd-key on one computer and install it via bootable USB on another computer? I know the bootable USB install is possible through bios but is it possible to download the ISO using just the CD-Key? Thanks