I am able to boot to Safe Mode.
I tried booting from the Win XP Setup CD but that started loading drivers and files, then when it said "Windows is Starting" just stopped exactly as it did during a normal start -- No progress and no HD activity.
I then swapped the HD for an older one with Windows ME installed. The Win ME splash screen displayed and there was HD activity. Then the splash screen changed to a blank screen with an hourglass cursor, the HD activity stopped, and nothing else happened.
I'm assuming some type of hardware problem at this point, so unplugged and reinstalled all cables. I reseated all cards. I even replaced the HD data cable. None of which helped.
Do you have any idea what could be "broken" that doesn't allow a normal startup but does allow a Safe Mode start?