We have an OEM PC with Windows 8.0 install. Due to application compatibility issue, we must re-install with Windows 8.1 32 bits. Asked Microsoft and they said only way is to restore PC to factory 8.0, then use the Pro pack key to upgrade it to Windows 8.0 Pro, and run Windows update to 8.1 Pro. Obviously a very tedious process. Lately I came across below article, I wonder if I can use the same trick - ie: re-activate Window 8.1 using the generic key, then apply the 8.0 Pro Pack key. thanks
http://superuser.com/questions/650019/how-to-use-windows-8-1-rtm-with-8-0-key