Problem Fixed !!!
On a whim I did a search for disk diagnostic utilities because I wanted to see if the hard disk might be repairable instead of replacing it. I found free diagnostic for IBM/Hitachi drives at:http://www.hgst.com/support/downloads/
I made made a diagnostic boot CD from the iso download of the Drive Fitness Test software from that site and ran it according to the instructions. It found a bad sector on the drive and gave me the choice of erasing the bad sector or erasing the entire disk. I figured I had nothing to lose so I chose to fix the sector. After about an hour it I got a clean report that there were no longer any errors on the drive. I removed the CD and rebooted. To my amazement and delight, XP started !!!! and proceeded to reinstall the drive and drive controllers (Im guessing that information was on the bad sector that I erased). All of the hardware reinstalled and I rebooted again. Voila !! Everything is back to normal.
Many thanks to EOMtp for his help.