After a quick Google, I beleive it is a part of the BIOS that identifies (autotypes) your hard drives, during the switch on phase.
It could be a corruption in the BIOS, possibly due to a fault, or a low battery.
Try resetting the CMOS - see your motherboard manual for the jumper to change over (power off first). Or/and try a new battery if that does not work.
When you say "Windows doesn't load" can you identify the sequence of events in detail when you get the error - and the exact error wording please.