How to view Windows 8/8.1 OEM product key from UEFI firmware (BIOS)?
Open an elevated command prompt and type (or copy and paste) the following command:
powershell "(Get-WmiObject -query ‘select * from SoftwareLicensingService’).OA3xOriginalProductKey"
Windows 8 Pro license transfer a new Windows 8.1 computer?
This product key is being used on another PC. Please try a different key.
Click on the Call support
The activation robot asks you how many PCs you have installed Windows on. The correct answer is number 1.