The CMOS is a small configuration chip on the motherboard of a desktop or laptop computer. It is battery powered and stores the date, time and computer configuration for the BIOS. It also stores the password for the BIOS. If you forget the password to enter your BIOS, you can reset the CMOS, which also resets your settings. In order to reset the CMOS on your HP Compaq Presario 5000, you need to disassemble the machine.
Prepare to disassemble the computer by unplugging it and removing the battery.
Loosen the two Phillips screws that hold the memory/mini PCI module cover in place. Lift the right side up and swing it to the left to remove it.
Disconnect the main and auxiliary cables from the Mini PCI module.
Release the Mini PCI communications device by spreading the two tabs on each side of the socket. Pull the module away from the socket to remove it, which exposes the real-time clock (RTC) battery.
Remove the RTC battery from the socket. Wait five minutes.
Replace the RTC battery and reassemble the computer.
Plug the computer into an outlet. Turn the computer on. The CMOS settings and password are cleared.