Yes I can think of a few things:
Try running the update with the anti virus and firewall turned off
A. run system restore, go back to a date before the problem started
Restore does not erase your personal files and is reversible.
click start
click all programs
click accessories
click system tools
click system restore
check the box that says restore my computer to an earlier time, click next
select a bold date on the calendar, a date before the problem started, click next
follow through with the restore directions
restart the computer after it finishes
if the system restore does not work, select an even earlier bold date on the calendar and repeat the procedure
try this with at least four earlier dates before giving up and trying something else
B. Delete the service packs and try re- installing them:
click my computer
click control panel
click add remove programs
Does it show SP3 installed? Delete it.
If you are able to delete SP3, start the install process over again by going to the MS update site. Install SP3 again with your antivirus and fire wall turned off.
C. Repair install XP with the system disk, without reformatting, if you have the disk.
then reload the motherboard drivers, reload all the updates.
But let's face it-- if all the above fails, some older computers it seems just can't run the updates.
As I have said before, as long as you have a good security system running, you really don't need the updates. And if the computer won't run the updates, you need to live with it.
Back up all your personal files to CD, DVD, online backup service such as Mozy, in case of future problems or failures.