Do the following:
Look at your windows version now (10 home or 10 pro)
After that run this command in an elevated command prompt:
wmic path softwarelicensingservice get OA3xOriginalProductKey
this will spit out the original key associated to your device. DO NOT TELL THAT TO ANYONE EXCEPT MICROSOFT SUPPORT.
Then run this command: slmgr /dlv
It will open up a window called windows script host. From there you will need to tell us the voice called Product key channel (the voice before installation ID) it is usually a 4 letter code. Does it say GVLK as such code?
Then you need to look at the Partial product key voice (the one after Id installation) does it have something in common with the key associated to your device? (are the 5 numbers or letter the same as a block of 5 of your original key?)
If not and if it says GVLK as channel of the product key it means that the device was activated via a fake KMS server. SO you need to do the following: run a command prompt with this written slmgr.vbs /upk <the partial key code you found in previous step>
At this point you will have uninstalled the fake KMS activation, try to go into windows activation again and type the original device key. If it does not work it means that either the key was used or you are running a different key for your version (pro key on home and vice versa).
At that point you need to call microsoft support and explain the issue, they will ask for your key and you have to tell them the key and they will be able to tell you whether the key was used or if it is for another version of windows.
Let me know ASAP
Archer
