To wipe a hard drive clean, use a third-party destruction program such as Darik's Boot And Nuke, or DBAN. An alternative software for the same purpose is Active@ KillDisk. Back up any important data that may be on the hard drive before running any of these programs.
To wipe the hard disk using DBAN, start off by downloading the ISO file from the DBAN website, then burn the image to either a disk or a USB device. Insert the disk or USB device into the computer with the hard drive, then restart the computer. Boot into the disk or the USB device.
Once DBAN's main menu appears, press F3 to open the Quick Commands screen or press the Enter key to open DBAN's interactive mode. The Quick Commands Screen lists the commands you can enter at the boot prompt. Each command uses a different wiping method. Proceed with caution as each command wipes all the disks on the computer without confirmation.
DBAN's interactive mode lets you choose the wiping method and the hard drives to wipe. Choose the appropriate options, then press F10. Wait for the wiping process to run to completion. After the wiping completes, a message saying that the wipe was successful appears.