There are several reasons a user may want to format a hard drive: to reinstall Windows, delete unwanted files, clean the computer of viruses or give the hard drive to a friend. Formatting the drive of a computer does not delete the data on the hard drive. Data on the hard drive essentially has pointers that reference the data and where it is stored. The format removes those pointers so the data is no longer accessible. There are several pieces of software that can find this data and retrieve it.
Insert the manufacturer’s CD into the computer.
Reboot the computer. Computers are set in the BIOS to boot from the CD/DVD first. If no bootable CD is recognised, the computer will boot off of the primary hard drive. In this case, the manufacturer’s bootable CD will start the installation process. If the computer boots off the drive first, reboot the computer again, and press the "F1" or "ESC" key (depending on model) at the initial boot-up screen to enter the BIOS.
Newer Toshiba laptops are tricky when entering the BIOS. Turn the computer on while holding down the "ESC" key. The computer will beep and display "Check System." Press the "F1" key. Release the "ESC" key. Press the "F1" key again.
Press the "Enter" key at the Welcome to Setup page.
Accept the licensing agreement if you agree to the terms.
Bypass the repair option. Most likely Windows will detect a previous installation on the computer. Windows set-up will prompt you to press "R" for repair. Press the "ESC" key to bypass the repair process.
Press the "D" key to delete the partition.
Press the "Enter" key to partition the drive.
Format the drive. There are two formatting options: FAT and NTFS. NTFS is suggested because it is more secure. Once Windows set-up is finished formatting the drive it will reboot the computer and start to reinstall Windows. If you do not want to reinstall Windows, shut off the computer at the initial boot-up screen.
If you want to remove the data from the hard drive permanently you need to use a utility such as WipeDrive. The only way to permanently remove the data on a drive is to fill the sector with other data.