If you have windows 95,98 or ME, create a boot disk. get one from
www.bootdisk.com, and reboot the computer from the A: drive. Once on the DOS
prompt just type, Format c:
If you have Windows NT, 2000 or XP, you need third party software to
reformat a hard drive, unless you have access to a second NTFS computer (One
running 2000 or later), If you have access to a second computer, remove the
hard drive from your computer and installed on the other computer as slave,
this way you can reformat it just by goint to My Computer and righ click on
the disk you want to format and select format.