CMOS Jumper
BIOS or Basic Input/Output System is a small program that facilitates the startup of a computer and enables communication with the hardware before an operating system is loaded. This software is housed on a ROM chip on the motherboard. Another ROM chip, the CMOS chip stores information that is subject to change such as time/date, power saving settings, and video adapter, hard drives and other device settings.
CMOS settings can be altered in the CMOS Setup, which can mostly be entered by pressing the DEL key or F2 key during startup (the keys differ from manufacturer to manufacturer. Please refer motherboard manual).
Most motherboards have a "Restore factory defaults" option in the CMOS setup software which can be selected to return to the settings that the chip was originally shipped with. Also, the motherboard has a jumper which allows you to return to the default CMOS settings configured by the manufacturer. This is useful when you cannot access the CMOS Setup because of incorrect CMOS settings or lost CMOS passwords. Make sure the power is completely off when you short the jumper.
