Why not install the OS fresh and add the drivers one by one until it either works or fails?
Today I no longer bother with trying to repair XP. The hours lost can't be recovered.
I have a Dell M60 Precision Workstation laptop that has recently become problematic booting. The system boots to the WinXP splash screen, continues to boot until the login screen should display. At this point the display becomes a splotchy gray color, lighter tones around the edges. After about 10 seconds the whole display progressively becomes a uniform light tone of gray from the edges in. There continues to be hard drive activity, but I just have to shut it down with the power button after the activity stops. The same thing happens with an external monitor connected through a port replicator.
However, I can successfully boot it in Safe Mode, check device manager and find no problems. I can restart out of Safe Mode into regular mode and all is fine. After I shut down completely and start up again, the display does the same thing. I have physically replaced the current drive with the original drive which was working fine when I replaced it with a larger drive. The system does exactly the same thing. Any suggestions on what might be wrong?