Came across an issue after a computer virus cleanup / repair. XP SP3 Automatic Updates was disabled and you could not turn it on. Ran across this program that repaired the problem in no time.

Download a small program called Dial-a-fix. Sorted out windows auto update in seconds.

http://wiki.lunarsoft.net/wiki/Dial-a-fix#Mirrors.2Fdownload_locations.2C_and_articles