Well, you could possibly rescue the drive. I've had to do it once from my stupidity of shutting down the car and letting windows finishing booting. Had an indentical symptom your describing. Anyways, I assume you have the origanol XP cd.
Before going ahead with this procedure, keep in mind it took my computer about 1 or 2 hours to fix itself. So if your going to do it, you may wanna transport the PC home to a power outlet.
Ok, now, pop in the XP cd and boot to the cd. When the Windows Setup program is up and running, you wanna to go into Repair mode. This will allow you to start into the Recovery Console. In there, you are going to have run a command "chkdsk /s/f/r"
Pretty sure thats command. When the process is done, windows should be up and running. Though, be warned, there may be broken components after the repair, but atleast it'll be working. Prolly easier just to format and make a Ghost image for the future.