Kingpin, do you know the model number of your motherboard? If not, was your PC a prebuilt system (ie Dell, Gateway, HP, etc)? If it was prebuilt, can you give us the exact model number from the label on the back/side/bottom?
This does sound like a setting in your BIOS but it will be easier to help you adjust the settings if we have an idea of what BIOS options are available to you.