New
#50
Generally, anything with Windows 7 on it will upgrade to Windows 10. When you say "not applicable", I'm not sure what you mean. Have you tried to upgrade it to Windows 10 and it said it can't upgrade? Or, do you mean you can't legally install Win 10 on it? If that's the case, anything running Windows 7 or Windows 8.1 is legal for Windows 10. Boot your Win 7 lappy and go here to see if it will upgrade: Windows 10 Just follow the yellow brick road.
I wasn't aware you could do that! :) Learn something new every day. Probably a trial version. Since you already have a working copy of Windows 10 on your computer, why not join the Insider Program? I tried to go there this AM, but the site is down, so can't give you a link.
Again, I haven't heard anything about that one. Since it worked for you, I guess it's legit. :)
Have you looked at Activation again to see if it's either activated or you have digital entitlement?
At one time, Newegg.com was selling product keys for Windows 10. I don't know if they'll accept your payment method, but if they will, that may be a source. Since you're a gamer, I'd get the Pro version rather than the Home version.