The OEM EULA states clearly that you can install it on a different machine as long as the previous machines get de-activated. This is great news and explains why no "Full Retail" $300 versions are for sale. It is even transferrable via a one-time sale if all paperwork and proof of purchase goes to new owner. I am a little less clear if the new owner can uninstall it from that machine (if sold with a PC) and then install it on a new machine for their own use. I like what MS has done here.