The CMOS battery is typically a small coin cell located on the motherboard.
The CMOS chip retains motherboard voltages, boot passwords, initial hardware configurations and the system clock information. Reset the CMOS on an HP Pavilion to remove a forgotten password or to solve problems caused by a failed overclocking attempt where the CPU and motherboard voltages were set too high and stability was lost. Boot passwords will be erased and all of the settings for memory, system components and the CPU will revert to a safe range allowing the system to boot. Solve system hangs, freezes, boot issues and overheating problems by returning all of the settings to the system default.
Instructions
1. Remove the power cord from the back of the computer.
2. Attach the end of the anti-static wrist strap to the computer case on bare metal if possible, and connect the other end to one wrist.
3. Remove the two large thumb screws from the case cover and slide the case cover about an inch to unlock it from the case, then lift the cover from the case to expose the motherboard.
4. Remove the small coin cell CMOS battery by pressing down gently on the retaining clip until the battery pops up out of the socket. Then wait 30 minutes.
5. Place one edge of the battery back into the socket under the fixed retainer and then push down on the battery to lock it into place.
6. Replace the cover and power cord and boot the system.
7. Save the new settings when prompted by the system when it boots for the first time.
Tags: from case, case cover, CMOS battery, coin cell, motherboard voltages, power cord, small coin