Is it possible to upgrade to Windows 10 Pro from 8.1 Pro retail version and keep 8.1? I've read this Win Super Site article about upgrading to reserve it for free before the July 29th deadline, like saving it for later, and either rolling back to 8.1 if in-place-upgraded from within 8.1 or reinstalling 8.1 if a clean install of 10 was performed. I presume the article's meaning of "clean install" doesn't necessarily mean buying a retail Windows 10 and installing, since this Thurrott article says it's possible to clean install 10 using retail product key of 8.1 and you can download the Win 10 USB/DVD/ISO creator from Microsoft. But this seems to contradict this Microsoft answer that says both:
What happens if I change my motherboard?...If the base qualifying license (Windows 7 or Windows 8.1) was a full retail version, then yes, you can transfer it.
- UPGRADES. To use upgrade software, you must first be licensed for the software that is eligible for the upgrade. Upon upgrade, this agreement takes the place of the agreement for the software you upgraded from. After you upgrade, you may no longer use the software you upgraded from
Which article/answer is correct? If the Microsoft answer is correct, is upgrading from an old retail version and reusing the old version simply disallowed by the terms and conditions but not actually enforced? Does the old version get disabled or force-upgraded upon connecting to the internet?
Despite what the Microsoft answer says about the ability to move an upgrade of a retail version to new systems, this Tech Republic article and many others suggest Win 10 in general is tied to the motherboard and there is no product key. So if reinstalling the old OS is disallowed, I cannot use it to upgrade to Win 10 and I'd unable to move Win 10 to a new system.