I've had systems whose BIOSes went into an infinite loop because a hard
drive was larger than they expected, or because two hard drives were
attached, or because the keyboard was not attached, or because the wrong
model of keyboard was attached, or because the machine was plugged into a
docking station with an attached display which was not made by the right
vendor.
These days I'm rather surprised if I attach *anything* I didn't buy with a
PC to the machine and the BIOS doesn't toss its cookies over the side.