New
#11
Whilst I agree about a clean install, I have never once needed a Windows 7 installation key nor needed to do an upgrade first... and I've done loads of Win 7-to-Win 10 clean installs.
Instead I just followed Brink's Clean Install Windows 10 Directly without having to Upgrade First tutorial. Worked every time without fail and activated immediately.
(I now keep a copy of gatherosstate.exe just in case it's ever needed for another Win 7-to-Win 10 clean install.)