The only thing that seems to cure it is to walk away for an hour or so. After this time has passed the system will boot up normally and Windows XP will load. Following this first successful boot of Windows I went ahead and installed all of my drivers (mobo, Vid card, sound card, etc.) thinking that this might enable the system to restart properly. It did not. I restarted the system after all the drivers were loaded and again the black screen.
What could cause this?