1) To repartition: When the option comes up in the installation, choose to repartition yiour drive. Delete all current partitions, and make the new ones you need (usually just 1 to keep it simple, as you are using NTFS).
2) To Wipe the data off your hard drive so it can't be recovered, if that's your aim: Go to
www.maxtor.com, click support, then english. Get PowerMax, and load it to a blank floppy disk (preferably a new one). Leave the disk IN THE DRIVE, and reboot the machine. When the option comes up, Zero the drive (if you choose the fill zero option, it will take a long time, so get some lunch, grab a beer, watch both Lord of the Rings movies on DVD, then watch all the special features, then go grab a midnight snack, go to sleep, wake up, go to work, come home, it should be done then

). Then reboot the machine (click exit, and shut off the machine with the switch (it's safe), and turn it back on), and remove the disk.