is it coming in using windows messenger?
if you are running xp or win2k check this:
"
1. Enter Administrative Tools (In Control Panels)
2. Double-Click the Services Icon
3. Locate the Messenger Server listed there in alphabetical order.
4. Double Click this Service and Options will appear.
5. In the drop down box for Startup Type, select "Disabled"
6. Under Service Status Click "Stop"
7. Click "Apply" and "OK"
This will disable all pop-up messages. "
gl