How do I find the product key for Windows 8.1

No the store upgrade does not generate a new key, the license for 8.1 is active on the original key.

The problem is the key cannot be used to activate a clean install of 8.1, you must install 8 1st and then upgrade.

This has been covered many times on this forum.

I downloaded Windows 8.1 (free) from the Microsoft web site. My understanding was that in doing so, a new product key would be generated. I do not know where/how to find the new product key. Can someone help me out with this? Was I mistaken and do I use the product key I have for Windows 8?

please guys help me

Notwithstanding what might work ultimately by installing Windows (any version) you agree to the terms of the EULA (End User License Agreement)

Now the legalese of what that means.

That is quite specific, you have bought one license for one installation of that version of software. The OEM Pro license allows for that installation to be to be downgraded to the previous version of Windows. The OEM license only allows the installation to be used on the original computer it was installed on and cannot be transferred to another computer and can only be used for the original version supplied by the manufacturer*. Support for OEM licenses shall be the responsibility of the manufacturer not Microsoft.

* OEM SKU packs are specifically 32 bit or 64 bit so although the same key could be used for either version even the manufacturer cannot provide the alternative disks.

I don't know what sanction Microsoft could apply but cases have been prosecuted.

Thanks, HairyFool.

My original intent was just to have all the licenses I bought stored safe somewhere in case system dies and I ever need to refer to them. I then found that article as to how the 8.1 Pro license could be useful in that other way.

I don't mean to bypass Microsoft licensing and I don't think I would be smart enough to do so anyway. I guess the way I view it is I actually bought 2 licenses - one for Win 7 and another for potential Win8.1 Pro upgrade. I did not plan on using the other one any time soon, if ever, but if I *can* use it for upgrading a (bought) Win10Home system to a Win10Pro, I would not think I am cheating Microsoft, because...

• I am using it for an allowed upgrade (after all, why allow a 8.1 or lower license for Win 10 upgrade? Must be Microsoft doing so on purpose)
• like you said, they could have easily stopped it based on hardware just like with other license (or even at manufacturer level, e.g. disallow install on non-HP PCs for keys issued to HP). I would take their systems allowing it to be a good sign that this is allowed on purpose, rather than some bug that still has not been fixed.
• the article I linked is from a well-known site and looks to be a well-distributed public knowledge since at least 2015 when this was published. I would assume if it were a bug on Microsoft part, it would be fixed by now, after two years (or longer?).

I guess my last question is if I take the plunge and go ahead with such an upgrade, and if such upgrade ends up successfully activating Win10Pro, do you think I am all set then or later I may discover that license will get revoked or time out somehow? (I understand this is just speculation, but curious what you would guess since you clearly have way more experience with this than me.)

Appreciate your help!