The unhackable BIOS exists for one very simple reason: the manufacturer wants this PC to work for the broadest, simplest set of PC users. In other words, it does not want to have to bear the cost of support calls related to hacked BIOS settings. Completely understandable if this is a family PC but very frustrating if you’re a real techie and wish to experiment. All hope may not be lost. Many vendors use the same or a similar version of system boards that you can get off the shelf or by mail order. Link.
Hack an Unhackable BIOS