Three Different Product Keys from Three Different Methods


Hi all,

I was following on How-To Geek which suggested a few different methods for recovering your Windows product key.

I tried a few of them and each produced a different key. I’m curious to know why.

The machine was originally Windows 8, but was upgraded to Windows 10 ages ago. There was no sticker, so I tried running the Powershell command, the NirSoft program, and the vbs script. Each produced different keys.

Does anyone have any thoughts on why this might be?


The VBS script does not work for anything other than Windows 7. The value is stored in the registry with a substitution cipher (A = X, B = Q, that kind of thing), and the cipher has changed after Windows 7. So the VBS script does not work.

The PowerShell method is slightly different…this allegedly pulls the product key that is stored in your computer’s firmware. This key is burned into the same flash memory that holds your EFI firmware (your BIOS) and is part of that physical computer for life. If you upgraded your Windows 10 license, or if your computer originally shipped with Windows 7 or Windows 8.1, this key will be different, as this is the original key, not the one generated as part of your digital entitlement when you upgraded.

I believe he only sure way to get the correct key for your current Windows install is the NirSoft method, as it takes into account which version of Windows you have and does the correct replacement cipher when reading the value from the registry.


The other thing to take into account is it is likely you don’t even need the key. If you do a fresh install of Windows 10 your computer will automatically re-register with Microsoft servers which basically have a fingerprint of your hardware; so your OS would automatically activate.

The only scenario where you might run into trouble is if you have replaced your motherboard, if you got the free Windows 10 upgrade then that isn’t the same as a retail license so you wouldn’t be able to reuse it in that scenario.

However, you could always install Windows 10 for free if you don’t mind a watermark on the bottom right of your screen.