I have been subscribed to the insider preview and had all the builds of Win 10 as they have been released when Win 10 went RTM I unsubscribed and installed Win 8 Pro and registered using my legit Win 8 Pro key afterwards I upgraded to Win 10 RTM from Microsoft updates and after activation I expected a new Win 10 key - in fact after activation the key is the generic key I was using for the preview builds but Windows is permanently activated, anybody else noticed this? The only thing I can think of is the Microsoft account that I have used to sign into both versions is the same one I've always used from Win 8!
When I upgraded my other computer which was running licensed copy of Win 8 and had never been used for the insider program I got a new Windows 10 key after upgrading, however when I reinstalled Win 8 on another machine that had previously been used on the insider program and then upgraded to Win 10 I did not receive a new key - its the same key that I have been using whilst running Win 10 Preview! So why do I get a new key on the machine that never was on the insider program and the machine that was stays with the generic key?
there are 2 generic keys . its all hardware based. i activated 5 machines. 3 early a week before release on leaks.all different accounts. all same key after. 1 was a 7 with daz loader to 10. different ms account same key. the last was a official upgrade and guess what same key.all different locations and ms id's. food for thought.