I have a genuine Windows 7 Home Basic product key. I also have a slow internet connection, so I purchased a disc and downloaded Windows 10 64-bit to the disc on my friend's computer.
After installing Windows 10, I was asked for the product key. Can I use the Windows 7 Home Basic product key on my Windows 10 install? If so, does that Windows 10 become genuine like my Windows 7 Home Basic?
I believe if you are activating Windows 10 and have already migrated and it is NOT activated, you will need to use the Windows 10 key. If you want to use the Windows 7 key on Windows 10 Windows 7 needs to activated and you have to go through Windows 7 to upgrade it. I'm unsure if you did the upgrade strictly through the disk. If you just inserted the disk and the system has no idea you have windows 7 then no you can't use the Window 7 key; however if you had downloaded the Windows 10 version while in an ACTIVATED Windows 7 you would not need the Windows 10 key.
Let me simplify.
If you upgraded straight from an activated Windows 7 after downloading Windows 10, Windows 10 would not ask for it to be activated, it would know of the previous version and already be good.
Windows 10 can't be activated with a previous key version of Windows E.g, a Windows 7 key. You HAVE to go through the upgrade process so Windows knows you are upgrading.
With Windows 10 TH2 (November 2015 Update) you can use your Windows 7 Key to activate Windows 10. This is a change since Build 10565:
Device activation improvements: We have received a lot of feedback from Insiders on making it easier to activate Windows 10 on devices that take advantage of the free upgrade offer to genuine Windows by using existing Windows 7, Windows 8 or Windows 8.1 product keys. If you install this build of the Windows 10 Insider Preview on a PC and it doesn’t automatically activate, you can enter the product key from Windows 7, Windows 8 or Windows 8.1 used to activate the prior Windows version on the same device to activate Windows 10 by going to Settings
Update & security > Activation and selecting Change Product Key. If you do a clean install of Windows 10 by booting off the media, you can also enter the product key from prior Windows versions on qualifying devices during setup.
