The CMOS battery is a small battery that is often attached to the motherboard of a computer or laptop. It is usually a type of watch battery, and can easily be replaced once located. It sometimes causes problems when the computer starts malfunctioning for no apparent reason. Before throwing your PC away, read these facts to diagnose your problem.
Note anything that seems strange, like if the screen blanks out or if the computer just does not run smoothly.
You will receive strange error messages such as: "CMOS Settings Wrong" or "CMOS Read Error."
Strange Computer Malfunctions
The computer might randomly shut itself off, or it could refuse to start.
You will have to reinstall programs again and again upon startup.
You will hear beeping coming from the computer, or the clock will start to tell the wrong time.