It seems to me that either you need to find the original XP CD or purchase a new copy from Compaq.
You may wish to ask Compaq nicely and they MAY send you a free replacement. I recently did this with Dell and they sent me, not only a Windows CD, but an updated utilities CD for my (student) daughter's laptop.
On another note, it is normal to use a thread title which actually describes your problem so that members can decide if they have the knowledge to help.
"URGENT HELP REQUIRED!" is of no use to any of us.