The CMOS remembers the time and date settings of the computer, and also remembers the Hardware settings.
CMOS settings are altered by the BIOS program while in setup mode.
CMOS or BIOS configuration settings
boot order
boot order
If the CMOS battery dies you lose the settings that are held in the BIOS (Basic Input Output System). These include settings such as date/time, boot order,etc.
CMOS battery
Data stored in CMOS can be altered using a CMOS editor program. CMOS commonly stores the computer's BIOS and its content can be changed using the inbuilt BIOS settings utility.
Current date and time
Data stored in CMOS can be altered using a CMOS editor program. CMOS commonly stores the computer's BIOS and its content can be changed using the inbuilt BIOS settings utility.
Its is the button battery that stores the BIOS settings for your computer.
When you enter the CMOS setup utility and make changes, your settings are stored in a small memory chip on the motherboard called the CMOS (Complementary Metal-Oxide-Semiconductor) chip. This chip retains the settings even when the computer is powered off, thanks to a small battery that supplies power to it. The settings typically include system time, hardware configuration, and boot order. If the battery fails, the CMOS settings can reset to default.
There is a small battery that powers the CMOS chip.