Windows 10: Product key being used by different device

I built a new pc about a week ago, installed a fresh version of windows purchased through a retailer, all of the sudden I’m getting the activate windows watermark and once I try to troubleshoot it says I cannot activate because my product key is already being used? I bought this copy of windows and immediately installed it on this computer, how is it being used by a different device?? Error code 0xc004c008

:)

 

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

I don't think so, not now. If the other PC was still running the original install where that key was entered, Yes, you could find the key. Once you reinstall Windows, and skip entering a key though, its not there to be found. The current Product ID will I think be based on the generic key. @Superfly knows more about that product ID stuff than I do.

 

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.

 

Devices and MS product keys

In my MS account, signed into account.microsoft.com, what page, and it's path can I find all my devices, the MS products and the product keys listed?

And yes, it does exist, different from the account.microsoft.com/services/ page.