Your computer's CMOS (Complimentary Metal-Oxide Semiconductor) is a small, battery-powered chip built into the motherboard. It stores basic data that is instrumental to your computer's operation, such as your computer's internal clock settings and data that allows your hardware to communicate with the operating system. Resetting the CMOS means removing and replacing the coin-cell CMOS battery; this requires partially dismantling the computer.
Instructions
1. Shut down your computer. Unplug the power cable from its socket on the computer's back panel. Disconnect any external devices from the computer. Rotate the computer so the back panel is facing you. Place the computer horizontally on its left side.
2. Remove the two Phillips-head thumb screws fastening the right-side access panel to the computer. Remove the side access panel from the computer to reveal the motherboard. Touch an unpainted metal surface to discharge static electricity from your body before working inside your computer. This prevents electrical damage to your computer's motherboard.
3. Locate the CMOS battery socket near the lower-left corner of the motherboard. The CMOS battery resembles a large watch battery. Lift the battery out of its socket and throw it away.
4. Place the new CMOS battery inside the empty socket with the "+" symbol facing upward. Replace the side access panel and its retaining thumb screws.
5. Place the computer vertically and reconnect the power cable and external devices.
Tags: CMOS battery, your computer, access panel, back panel, battery socket