Zoostorm suck - I know many people have bought them only to return them after only a few weeks or even days! Me and a friend troubleshoot PCs as a hobby, and I've had more Zoostorm, Dell and HP computers than any other brand!
To do a complete reinstall you will need your Windows XP disc. Open the CD tray, insert the disc and then restart. Now it should automatically boot from the CD, if not, you will need to set up the system temporarily so it boots from the CD drive, and not from the primary hard drive - this will vary by system, so I can't give precise instructions on this part. Remember to return this setting back to primary hard drive as first boot device once you have reinstalled XP.
Bear in mind that a complete reinstall will wipe out EVERYTHING on your drive, so be sure that you have backups of all programs, files etc.
Electric Dragon, March 2009