posted on Jul, 24 2011 @ 07:00 AM
I'm assuming you want to wipe it entirely out and start all over from scratch.
I would download DBAN
from the internet, burn it to CD, boot from the CD and securely wipe out your hard drive.
Then start over with whatever original operating system disks came with your computer.
Be careful with DBAN though, once you tell it to start wiping it will. Remove any other drive (external, USB stick) from your computer before you boot
with the DBAN CD. It does not give you a warning like windows does (Are you sure?)