TSGL: System will not boot

[Ron Grant]

I have a system that will not boot.
Here is what I know about it.

Dell Dimesion XPS T 450
Bios version AO4
Intell Pentium 3 processor
Windows XP Pro

When starting a boot it will run through a memory check screen, then the Windows XP pro screen.  Shortly after 
that a blue screen flashes very quickly and returns to Mem test screen and attempts to boot again.   It will 
run through this cycle indefinitely.

The owner stated to me he was updating via windows update.  (SP2 I think)  something happened and he tried to 
uninstall the update.  when rebooting after the uninstall, it will not boot.

I can get to the bios and the choice screen to choose safe mode and other choices, but the result is always 
the same.  After the Win XP screen a blue screen flashes and the cycle starts again.
If I run Directory Services Restore mode, it runs a check on drive C, and states that the system is clean.

Any ideas on how I can restore this system?
Thanks,  Ron