Must a clean install be on the same machine to Activate with a Win 7

Must a clean install be on the same machine to Activate with a Win 7 or 8 key?

You don't need to enter a key at all if you are activated on 10 already when doing a clean install.

If you enter a key it will tell you it is use and not accept it if you have used it elsewhere

At least it did for me when I tried to activate a generation 2 Hyper-V VM after a generation 1 VM (made by mistake) with same key. Second activation my 7 key was rejected as it was "in use on another computer"

lx07 said:

You don't need to enter a key at all if you are activated on 10 already when doing a clean install.

If you enter a key it will tell you it is use and not accept it if you have used it elsewhere

At least it did for me when I tried to activate a generation 2 Hyper-V VM after a generation 1 VM (made by mistake) with same key. Second activation my 7 key was rejected as it was "in use on another computer"

just clean installed on Hyper-V, used another key. Success.