Using the current device's product key on my another device.

On old PC:
Uninstall retail product key:

1. Disable secure boot(if turned on in BIOS)
2. Boot into Windows
3. Enter slmgr /upk and wait for this to complete. This will uninstall the current product key from Windows and put it into an unlicensed state.
4. Enter slmgr /cpky and wait for this to complete. This will remove the product key from the registry if it's still there.
5. Restart
6. Wait a little while and then use the retail key on the new machine.
7. Set up secure boot(recommended)

Your old machine should go back to home, or you might need to do a clean install, I'm not sure there.

NavyLCDR said:

A clean install of Windows 10 Home will be needed on the old computer.

Thanks, I thought so,
but wasn't "quite" sure

RK1997 said:

Hello,
My 6 year old PC has Windows 10 PRO (Retail License). It came with Windows 7 Home which also was successfully upgraded to Windows 10 Home (OEM License). Now, I have bought a new PC which came with Windows 10 Home. How do I use my retail PRO product key in my new laptop for upgrading to Pro? I also asked the Microsoft Community but they were unable to solve my problem (Using the current devices product key on my another device. - Microsoft Community).

A retail key should work on new hardware... I've even used my OEM key on multiple VM's and they activated fine. (which should not have)

If it fails there are a multitude of reasons - not necessarily key related.

I do not frequent that forum but I would have expected more informed answers...since those are MVP's right?

Superfly said:

A retail key should work on new hardware... I've even used my OEM key on multiple VM's and they activated fine. (which should not have)

If it fails there are a multitude of reasons - not necessarily key related.

I do not frequent that forum but I would have expected more informed answers...since those are MVP's right?

There are MVP's there, non MVP's can also respond. Also MVP's have to watch what they say there, and basically toe the line. Acceptable use etc, if you know what I mean.

RK1997 said:

Hello,
I did a clean install of Windows 10 Home on my old PC using Windows 7 Home Basic key which was activated successfully. Yet, when I go to the store through Windows Activation page, it doesn't ask me any price for Pro upgrade but in my new PC, it asks. I have the same account on both PCs. Shall I just enter my Pro product key there? I have also posted the store's pic on the Microsoft thread if you wish to check.

My best guess is on the old PC it knows there is a Pro Digital License for that PC stored on the activation server. Upgrading to Pro on that PC would be free as it already has a DL for Pro.
The new Pc doesn't have a DL for Pro stored, so its asking you to enter a key, or buy a key. You could enter the key there. Or just go to Settings > Update & Security > Activation and do a change Product Key. Either way should get you pro on the new PC. You may be prompted to transfer the licence to the new PC, not sure, I've never done a product code transfer from one PC to another.