Create an XP startup disk, boot using this and then try a scan disk. I have had some verious issues with XP not starting or shutting down properly, normally shutting down the system (holding the power button till power off) and restarting has eventually resolved the issue.

Also, try to boot it into the Modes (F8) and select "use previous configurations that worked"

This happened to me too. Please help:
* Bought a new pc and uninstalled programs on the old one, because I wanted to sell it. Rebooted it and winXP wouldn't start, the pc would reboot by itself over and over. I tried using the WINXP install disk but the pc wouldn't boot from the cd. So I took the hard drive and put it in the new pc. This way I was able to restore windows and the new HD was working properly.
* I thought I had solved the problem, sold the pc to a friend who then called me to tell me the pc wasn't working. I took it home and yeaph, WIN doesn't start, it boots up normally but when windows is about to start the screen goes black with a white blinking cursor on the left corner. This HD works normally on the new pc. Someone told me either the processor or the memory might be burned... is this true?

Thanks for any light on this subject.

Im having the same problem with a friends computer, I took the computer home to see if I could fix it. It just loads to a blank black screen with a flashing cursor!!! Ive tried everythinh, recovery, rescue disk, windows xp cd....list goes on and on....some one please HELP ME.....ITS DRIVING ME NUTS!!! Any help would be greatful