Does the OEM product key on an upgrade to windows 10 require a 10 or 8 installation?

[Ty_14]

My brother's laptop has been offline for a couple months due to a mix up in ordering a new charger. Upon starting it back up after finally getting said charger, Windows is having issues starting up. It's attempting and failing to diagnose the issue using the Windows Startup Repair. (I suspect this might be due to a corrupted registry, but cannot confirm) My brother doesn't care at this point if I delete everything and start anew, however, I am aware that his laptop originally came with Windows 8 OEM and was since upgraded to Windows 10. I am also aware that the product key is embedded in the UEFI/BIOS. My question is, if I do a fresh install of windows will the product key activate an installation of Windows 10 or do I have to go back to Windows 8?

 

[ThatVietGuy]

The license is tied to your Microsoft account, not the motherboard (not anymore, anyway) - https://support.microsoft.com/en-us/help/20530/windows-10-reactivating-after-hardware-change

If you can't get this done after what's happened with the original installation, you can install Windows 10 and then call Microsoft for assistance in reactivating.

 

[Colif]

@ the vietguy: It can actually be either now. If you never logged into a PC with Anniversary edition or later installed, with an account linked to an email address, it can still be tied to the motherboard. That is how mine is.

@ op. what Thatvietguy said might be true, it depends how brother logged in.
What I would do is clean install win 10 and when you reach screen asking for the license key, click "I don't have a key" and win 10 will continue the install. Then once its completed, it will check the activation servers and then you will find out if PC linked to hardware or email address.

You don't need to install 8 as when your brother upgraded to win 10 it created a win 10 license for the PC.

 

[canadianvice]

It should be activated. Worst case scenario, Microsoft is being very liberal with W7 and W8(.1) keys in activating 10. I don't foresee you'll have any issues; basically, when it asks for the key during your install, just opt to skip that step, and once the PC is good and online, it should automatically figure things out.

If not, just enter the key as you have it and you should still be sitting pretty.