If you haven't noticed, those annoying pop ups have now started to use the messaging program on your computer to sell there products (80% porn sites). The messaging program is designed for sending messages to other stations on your network, normally admin warning there system will be down for a bit etc.
You can easily stop 100% of these type messages by following these FREE simply instructions:
Windows 2000
Click Start->Programs->Administrative Tools->Services
Scroll down and highlight "Messenger"
Right-click the highlighted line and choose Properties.
Click the STOP button.
Select Disable or Manual in the Startup Type scroll bar
Click OK
Windows XP
Click Start->Control Panel
Click Performance and Maintenance
Click Administrative Tools
Double click Services
Scroll down and highlight "Messenger"
Right-click the highlighted line and choose Properties.
Click the STOP button.
Select Disable or Manual in the Startup Type scroll bar
Click OK
i hope i helped use