WindowsXP recovery from Windows 2000?

[Kestrel]

I have a system which had Windows XP Proffesional pre-installed as the OS. A while ago, XP began displaying the "Blue Screen of Death" and would not allow me to get back into the system at all, dispite trying all the options avaliable on the advanced boot screen ( F8 ). After an exhaustive effort, I finally decided to borrow a copy of Windows 2x off a friend, install it, and see if I could get back into my system that way - not realizing at the time that installing windows 2x on top of XP would lessen my chances of recovering the XP platform even further. (honestly, it's been a couple of weeks, and I've been trying a million things to fix it as well as a load of research on the net for everything that I can possibly think of - as far as what the specific error was that was bringing up the BSOD in XP, I can't remember.)

The computer was given as a gift to my wife and I with windows XP already installed on it, so unfortunately I do not have a Windows XP CD-ROM from which to work with - otherwise I'd have probably fixed the system by now.
Any help would be appreciated.