A few weeks ago, I posted an article on this site, entitled Stop those pop-ups (part 2), describing how to get rid of those nasty, obnoxious, annoying pop-up windows that seem to be afflicting just about everyone with a computer running Windows XP.
After checking in with some newsgroups, I’m now convinced that this is the #1 complaint of Windows XP users. These things seem to come out of nowhere, because the Messenger service (again, not to be confused with the Windows Messenger instant messaging program!) wasn’t a part of Windows 95/98/Me. Most people assume that they’re related to the pop-ups spawned by Web browsers. They’re not. They’re direct PC-to-PC messages from a sleazy spammer to you.
In fact, you should consider these pop-ups a great test of your PC’s security. If you’re getting these messages, your computer is dangerously exposed to hackers, crackers, and other attackers. You can shut down the Messenger service, as I outline in the article above, but that only solves the immediate symptom. To protect yourself from other, similar vulnerabilities, I highly recommend that you install a hardware router with port-blocking capabilities, or a software firewall, or both.