How do I find the product key for Windows 8.1

Hi  im don't now im bay this computer sekend hand 1 month a go

Thank you, Mark

Hi HairyFool,

You mentioned: "Microsoft did relax the rules a bit with the Windows 10 free upgrade being activated by a Windows 7 key in certain circumstances."

I looked around regarding this and came across this article:

http://www.zdnet.com/article/going-pro-how-to-upgrade-windows-10-home-without-hassles/

It says ...

"In particular, it means that old product keys you might have lying around are suddenly worthwhile. For example, Microsoft sold heavily discounted upgrades to Windows 8 Pro in the first few months after launch.

...

Those keys can be reused to enable an upgrade from Windows 10 Home to Windows 10 Pro"

and then suggests how to do that by using generic key and then activating using the Win 8[.1] Pro key.

Is this what you are referring to? And if so, would the other key I found work for this purpose?

Note: what I found was based on a script that decodes registry keys. The Win7 key you mentioned came from decoding DigitalProductId value whereas the other value came from DigitalProductId4 value (under HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion)

The same key is used for 32bit and 64bit Windows 7 although strictly speaking it is only valid for the original version, academic really because as I said the key cannot be used by entry and is integrated into the factory image. On the system I had with downgrade rights applied from the factory it came with the Windows 8 DVD and you made the recovery disks to get the Windows 7 restore.

Current Keyfinders know about the BIOS stored Windows 8/10 full key so I suspect that is the second key you have found, one decoded from the Windows 7 registry and one from the BIOS. For this downgrade system to work the BIOS needs its Windows 7 tag and the Windows 8 key at the same time

The 25 character contains the Product ID ( the real license number) and therefore is specific to the version. Microsoft did relax the rules a bit with the Windows 10 free upgrade being activated by a Windows 7 key in certain circumstances. The Windows 7 tag (actually called the SLIC) is also version specific, a Home system has a different one to a Pro.

Don't carry this through to Windows 10 as that has another system.

Thank you, HairyFool.

I indeed found xxx-6P6GT key on the Win 7 notebook (though I think it's a 32-bit key and I see another key there which ends in xxx-xxVP7 (maybe because this is 64 bit?)).

In any case, if I did install Win 8.1 Pro on this computer using the supplied DVD, which key would it use then? I assume it could not be those generic Win 7 Pro keys since those are specific to Win 7 Pro.

Since BIOS has that tag you mentioned, would I be able to then upgrade to any Windows version in future without any key?  (That seems unlikely)

If I were to install Win 8.1 Pro upgrade using the supplied DVD, it would also use some generic common key, or would it be a unique key for me?

If it's a unique key, is there some way for me to find it without installing the Win 8.1 Pro by reading it from somewhere?