Your computer’s BIOS (basic input/output system) is the low-level software that starts when you boot your computer. It performs a POST (power-on self test), initializes your computer’s hardware, and passes control over to the boot loader on a connected device. The boot loader then boots your operating system – Windows, Linux, or whatever else you’re using. The BIOS has a setup screen, which is used to configure a variety of low-level system settings.
Whether you’re using a desktop computer or a laptop, your computer’s motherboard contains an integrated battery. Unlike a standard laptop battery, the motherboard’s battery doesn’t power your computer while you’re using it. Quite the opposite, actually – the battery is tiny and only active when you’re not actually using your computer.
What happens when you start up your PC? In most cases (and putting it very simply), after the power switch has controlled the flow of electricity to the motherboard and the fans have started up, your hard disk drive will be initialized and the boot section read. From here, the operating system will load up from the hard disk drive. But what if you don’t want it to? Then, you would need to change the boot order for your computer.