Well I'm only going on past experience, but 9 times out of 10, that is the problem.
Unfortunately, enough BIOS setup writers either see that value as "dangerous" (which is completely WRONG; it can't possibly break anything unless the default is on; in all the cases where it's a problem, the default is off), or they're just so locked into the MS way of doing stuff that they can't see any possible use for such a setting.
In either case, the BIOS writer needs a good LART. Unfortunately, there isn't much we (as users) can do about it, other than just stay away from all preassembled machines (very few Dell or Gateway (let alone Compaq and friends) machines that I have ever seen let you do much in the BIOS other than change the time and the boot order), and any motherboard manufacturer that is that closed-minded.
Anyway, I'll get off my soapbox now.