> One day Windows XP decided to automatically try to dial-up to the internet upon
> startup, something I do not want, and I dont know whats causing it or how to
> stop it. Oddly though, Ive noticed that it doesnt do this if Unreal Tournament
> 2004 disc is in my DVD drive. Anyone have any clues on how to stop this? Help is
> greatly appreciated, thanks.

To answer the question you asked, open IE, go to Tools>Internet Options…, select Connections, and click "Dial blah blah blah not present." If that doesn't cure it, try "Never blah blah blah."

To answer the question you didn't ask, grab AdAware, SpyBot, and any others you can think of, and check for dialers.

I'd also try try other discs in the drive to see if they curb your box's behavior problems. If not, try uninstalling UT2004 just for shits and giggles.