Can PC boot without CMOS?

The CMOS battery is not there to provide power to the computer when it is in operation, it is there to maintain a small amount of power to the CMOS when the computer is powered off and unplugged. … Without the CMOS battery, you would need to reset the clock every time you turned on the computer.

Why does a computer need a BIOS?

In a nutshell, computer devices need BIOS to perform three key functions. The two most critical ones are initializing and testing hardware components; and loading the Operating System. These are essential to the start-up process. … This enables OS and application programs to interact with I/O devices.