I am using Windows XP and I occassionaly get a pop-up spam message out of nowhere. Even when I restart my computer, I still get it eventually. It appears at random times, sometimes it might take a day to get it, other times maybe 45 minutes. I am using AdWare and AdWare doesn't pick up anything unusual. How can I go about getting rid of this thing and preventing more of them from coming back? The title of the window shows up as "Messenger Service", though no messengers are running.

DigitalManiac