Haunted "Puter?

I'm not sure if this is a software problem, but since I don't know what it is, I figured I'd start here. My machine has started a new 'trick' as of late....it turns itself on!! This has been going on for about 2 days now and it's driving me nuts!! The machine runs great, except for this little quirk!
I'm running Win2000Pro (SP4) and the only new thing I added was a wired router so I can connect my son's machine to this one. Oh yeah, and Nortons Internet Security Suite. ANY ideas, anyone? When I shut it down it does shut down normally, but within 15-20 minutes it turns itself back on. The ONLY way to keep it off is to turn off the power supply. I don't have it set for stand-by or hibernation, or anything like that, so I'm at a loss. Any assistance will be taken into consideration for your next promotion and raise!! THANKS!!!!

 

I have a computer that does this when the phone rings. I think there is a network option for something similar too. If it is something like this, it will be in the BIOS.

 

So if the only new change is adding your son's computer to your network, do you have "wake on LAN" activation settings set, as this would cause your PC to come on if your son was accessing his PC possibly?

 

Sorry it took so long to get back with ya'll Anyhow, it appears that you were both right on and the 'ghost' has now left my 'puter Bill, the problem was in the BIOS and Lev, it was the 'wake on LAN' that was enabled, which I disabled. There was another entry right below that one....something about using the on-board LAN chip and I disabled that too!! Thanks ALOT you two!! If you wouldn't have pointed me in the right direction my next step was to take my machine to an exorcist!!! Thanks again, your help was much appreicated!!