first i would backup your important data first. this means copying it to another hard disk or burn them to CD, ZIP, whatever. put the win2000 or winXP CD into your cd-rom drive and restart the computer. at bootup it might ask you "press a key to boot from CD". once you boot to CD follow the directions. if you want to start fresh delete the partition and than create it again. be careful, this is very destructive if you delete the worng one. when you setup win2000 or XP format with NTFS, do not use the (quick) options, do a full NTFS format.