Hi all. Just sharing this piece of information because it has recently come to my attention that loads of people, even within tech communities, don't know about it at all. Microsoft have not publicized it or made any official announcements to suggest it would be the case. Nobody talks about it online. But in case you weren't aware, it is true - original Windows 7 COA license keys will also activate the corresponding (i.e. Home/Pro) version of retail Windows 10. I don't know why it be like it is, but it do. Once bound to a particular machine, they don't seem to stick to the hardware the way the digital entitlements from upgrades do, either - a key can be reactivated on different hardware at a later date, with at most a telephone activation release, though I expect repeatedly cycling a key around in a short period of time will get it permanently blacklisted, and indeed, I have come across a couple of keys that are simply non-functional.