Automatic Updates in Windows XP
I really hate these Automatic Updates in Windows.
I'm not against the Automatic Updates themselves, but the dialog that follows, and that only gives you 2 options:
Restart Now and Restart Later:

Why to complain? It gives you the opportunity to dismiss the dialog by clicking the "Restart Later" button.
That's true, but for 5 minutes only. After this grace period, the dialog is back, thumbing its nose at you....
And after a few "Restart Later", you finally give up and restart the machine.
So far, I was stopping the "Automatic Update" service when the dialog was popping up.
However, a support engineer from our Java tech. team came up with a better solution he found on a blog:
you can disable the auto-restart for the Automatic Updates installations.
See more information on this blog: "XP Automatic Update Nagging"