Hey guys, I've recently upgraded to windows 10 and made a mistake. I activated the office 2016 preview with KMS. For whatever reason, my vaild windows 10 product key got overwritten too, acoording to the changed PID. What should I do? Do I need to go back to win 7 and Upgrade again? Thx for the help
Oh, my dirty eyes! I think you can just do this in command prompt: slmgr -ipk key number here Or go into Update & Security > Activation in Settings app and enter the key.