@Fairfax
Do you have any reason to believe that your laptop failed on the grounds of the Microsoft update site assessing that its hardware specification was insufficient to run Windows 10?
You say it is Win 7 now but did it start life as a Win XP machine? Or something even earlier than that?
I was given to understand that some form of remote hardware check is performed by the Microsoft Update site.
I recall that one of the pitfalls of upgrading hardware under Win XP is that you are only allowed 4 or 5 goes at repeating the "Activate Windows" step (set of keys icon). This is enough to allow a domestic user to replace motherboard or HDD a few times, ocer several years but not so much as to allow someone to pass the master CD around a bunch of pals.
A machine which never passed valudation at Win XP or Win 7 level, naturally, would not qualify for the freebie.
I'm not casting aspertions, merely stating the facts. If you buy second hand you have no way of knowing the machine's upgrade history, let alone the vendor's honesty level.