How do I find the product key for Windows 8.1

As I said Microsoft have been more flexible of late but rarely declare anything unambiguously so I can't say precisely what would happen. The free upgrade program ended last year and that is the stated case.

Then we find that those using assistive technologies got an exception.

I was upgrading a system that missed out on the free offer due to incompatibility with a particular software package. That had been resolved and I spoke to sales with a question, when I said WHY we were doing the upgrade I was issued a license FOC even though I was not asking for it.

Ultimately all you can do is try. As to the second key the fact is I don't know what that second key might be because the situation is slightly confused by the fact it is a downgrade entitlement system..

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)

No, just the opposite.

Windows 7 major manufacturer OEMs disk have the key on the disk but each manufacturer has a single key for a particular version of Windows so for HP 7 Pro ends -6P6GT. It does not matter that we know the key because when HP sell a computer with Windows 7 preinstalled they put a tag on the BIOS to say the computer has a valid license but not the key itself. Each manufacturer has its own tag so the HP disk will not run on a Dell or a home build.

This has the handicap that ONLY the disks provided by the manufacturer can be used, even if you know the key it still won't work with a standard disk because the activation servers will not accept it.

Windows 8 Computers have the key itself in the BIOS and can run any valid disk for the version of Windows. The Activation engine within Windows will check to see if the key is present and not ask for a key when found. This is why you don't have a key label or any other documented version, it shouldn't be needed. If you extract the key it cannot be used to activate another computer because the Activation Engine does not allow it to be keyed in on the wrong PC. 

One common but incorrect scenario was the installation of Feature pack such as the Pro Upgrade because the dialogue asks for a key. People assumed it wanted the system key but FP's had to be bought and had their own key issued on purchase. I see the question asked frequently but personally I have never needed to use the key.

HairyFool, appreciate your response but wanted to clarify... in the case I described, I purchased "HP 350 G1 Notebook Intel ... Windows 7 Professional 64-Bit with Windows 8.1 Pro License". The Win7 notebook shipped to me with that Win 8.1 Pro DVD.

Are you saying that my Win 8.1 Pro key is on the DVD itself? So I can plug that DVD into any computer and use a key finder to read it off of DVD without installing Win 8.1 on that system? Which key finder would work for this?

I think you are also saying that 8.1 Pro key cannot be used on any other computer and can ONLY be used on the Win 7 notebook that DVD was shipped with. Is that right? In other words, it's a special license key that will ONLY work on one notebook in the world?

Thank you!

P.S. I don't recall exactly all the situations where such key would be useful but I remember reading online one should always extract and write down the key they purchased for various useful scenarios. I was able to find my Win 7 key using built in tool (wmic i think), but for completeness also wanted to extract and write down 8.1 key too.