Messenger pop-ups when offline and not signed in

[perplexed_one]

a small window above the system tray pops up when you sign onto Messenger right? well the problem ive been getting is when im not signed in, the window randomly pops up with weird usernames ive never heard of and when i click on them they open up convo windows.

im just wondering if i might have a worm (ive done scans with AVG)

[Kevinck]

Most likely it's an exploit of the Windows Messenger Service which has nothing to do with the chat application called Windows Messenger.

Do a start->run and type in services.msc

Scroll down to "Messenger" and stop the service. Also set the startup type to disabled. Assuming you don't also have a spyware infection that'll fix the popup balloons.