Formatting a computer is the process of deleting all information currently on the hard drive. This is done as an extreme step when changing operating systems or when your computer is infested with a virus. Formatting a computer requires that you set up the process through the BIOS, enabling your computer to avoid loading the operating system, as the computer cannot be fully formatted while the OS is running.
Insert the boot disc into the computer and restart it.
Press the key indicated during the startup messages (typically one of the "F" keys) to enter BIOS.
Click the "Boot Options" menu and select "Primary Boot Device."
Select the type of drive containing the boot disc, whether the floppy drive or the CD drive. Press "Enter" to confirm.
Press "Esc" and "Y" to reset. Press any key when prompted to boot from the disc.
Type "format c:" and press "Enter." Press "Y" to confirm.