Internet customers can receive spam in the form of a Windows pop-up on Windows XP/2000/NT machines. This Windows pop-up is made possible by a service called Windows Messenger (not to be confused with MSN Messenger), which is installed by default on XP/2000/NT machines.

While this service does not allow remote access to information on an individual's computer, it can provide a conduit for unsolicited messages or advertising. An individual can identify a message as being sent through Windows Messenger by examining the title bar of the window. The words "Messenger Service" will appear in the title bar indicate that you have Windows Messenger Services enabled.

Instructions for Disabling Windows Messenger Pop Ups:

Windows XP

Click on the Start button and open the control panel.
Open the Performance and Maintenance control panel and go to Administrative Tools.
Now double-click on Services, then scroll to Messenger.
Double-click Messenger and click Stop to stop the service.
Change the startup type to Disable and click Apply at the bottom.
Click OK to exit window.

Windows 2000

Click on the Start button -> Settings -> Control Panel.
Double click on Administrative Tools.
Now double-click on Services, then scroll to Messenger.
Double-click Messenger and click Stop to stop the service.
Change the startup type to Disable and click Apply at the bottom.
Click OK to exit window.

Another method to rid your system of this annoyance is to block NetBIOS ports 135, 137, 138. and 139 through the firewall. Each firewall uses a different method of blocking ports. Consult the firewall documentation or website for information on the proper procedure.