Wipe Hard Disk How Do I Wipe A Hard Disk Clean On An Older Computer?

How do I wipe a hard disk clean on an older computer? - wipe hard disk

My mother has an old computer with Windows ME. I tried several times to reinstall, but not always after installing new. Purify I clean the hard drive and install Windows Me on a clean hard drive. Unfortunately I have forgotten how. Can anyone help me with this? I delete everything from this disk, Windows ME, but did not let me. What should I do?