I downloaded the Windows 8.1 RTM ISO from TechNet today and wanted to test it on a Thinkpad W530 I have here that has a Windows 8 Pro OEM licence.
When I mounted the ISO and ran the setup it's prompting for a product key. I'm confused because my understanding is the product key is stored in the UEFI bios and I was expecting the 8.1 setup to detect it. During the original Windows 8 installation it never prompted for the product key and activated without issue.
I've checked my product keys on TechNet and I have 3 unclaimed keys for 8.1 that I assume would work but It'd be preferable for me to retain my OEM licence.
I used Magic Jellybean to obtain the OEM key but the 8.1 setup won't accept it and returns "That key can't be used to activate this edition of Windows. Please try a different key."
Any ideas?