Do you have everything needed to do this? Do you have a Windows XP cd,
a correct and valid Product Key (or COA number), the necessary drivers
for the laptop... without those you will quickly find yourself up the
proverbial creek and making your way down may end up being costly!
What make and model of laptop is this? Many laptops have a restore
image on a hidden Service Partition, when the restore process is
launched it wipes everything off the computer and restores it to factory
conditions, as it was when it left the factory. Have you verified to
see if your laptop has such a feature? Did you visit the laptop
manufacturer's web site to see if the information you need is available
there?
John