Why am I receiving pop-up messages from the Windows Messenger service or NetSend?

Windows NT, 2000, and XP have a service called Messenger that allows messages to be sent one way to a computer. This service is useful for administrators to send notices to individual computers, for example, to notify users who are connected to a server that it is going off line, or to notify a user that a print job has been printed. Recently, people have started using this service to send advertisements.

Although having a firewall on your organization's network or on your personal computer is a good security practice, it would be difficult and perhaps impossible to configure a firewall to block all the ports on which the messaging service listens without disrupting networking functionality.

An easy way to block unwanted Messenger service pop-ups is to disable Windows Messenger altogether. For more information about disabling this service, see How do I disable the Windows Messenger service?

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