Popup window opens up and disappears..

Hi, this is driving me NUTS!
No matter what I'm doing, something tries to 'run' every few minutes. I see a 'popup' that stays minimized and only lasts about 1 second then closes. If I'm doing something important.... like a raid in World Of Warcraft, WoW will minimize.
I had this happen before and ended up formatting... I have Windows finally running the way I want and don't want to start over again! Please help!

I haven't installed anything recently and I'm a pretty safe user.
I've run Spybot S&D and Ad-Aware. Nothing major picked up and nothing out of the ordinary in the event viewer..so I'm at a loss.

My computer:

Gigabyte K8 Triton motherboard
AMD 64 3000
2 Gigs DDR2 Corsair
GeForce 6800 GT
Windows XP Pro
Norton Antivirus Corporate Edition

Any help will be greatly appreciated!
Thanks!
Marc

 

Does the minimized popup have some sort of name?

 

No, just the small white generic window icon.