That's not my experience at all, and I strongly recommend *against*
uninstalling it.
I had two failed installs of SP3 both dealing with the automatic updates, and here's what my friend suggested who works on computers
for a living, and it worked.
Reinstall XP SP3, but make sure when you install XP SP3 this time that you have automatic updates turned off. Then after you get to
the desktop and have Internet access, use the Internet Explorer 6 that comes with SP3 to go to the Windows Update site and install
all the remaining critical updates from there. (You might have to install a Windows Update Active X update first in order to use
the site, and as I recall for some reason it didn't give me the option to uncheck any critical items like the automatic update did,
and it includes IE7 as a "critical" update, but it sure seemed like it took a lot less time than the automatic update process took,
things went a lot smoother, and I haven't had any problems with SP3 since. Make sure that you have every critical update that you
need before you leave the site and then when you get back to the desktop turn automatic updates back on. (I have it turned on now,
but I ask it to inform me what I want to do first.) Hope that helps.
Larry W.