The CMOS battery is an often overlooked but crucial element. Hidden on the motherboard of your computer, it acts like an emergency power supply for the BIOS.

While storing BIOS/UEFI preferences can be offloaded to say your Hard Disk, since it is non-volatile, a battery is required to keep the time and date in check (Real Time Clock).

If something has gone catastrophically wrong with your PC, you may need to reset the CMOS to solve the problem. Here's what you need to know.

I told her to check the settings in the BIOS and they were all reset to default. Also, the time was reset to 2002. This is all strong evidence that the CMOS battery needs to be replaced.