Stop Pop-Up Spam Messages
In a new low, spammers are now abusing a seemingly-innocuous feature in Windows 2000 and Windows XP systems to place pop-up messages on systems with high-speed connections to the Internet.
The NET command is used to send such messages (e.g. net send * Hello World), and the messenger service (different than Windows Messenger) allows users to receive such text messages.
By default, it is running and active on all Windows 2000 and Windows XP systems. Here's how to turn it off:
1. Open the Services window (services.msc).
2. Double-click the Messenger entry in the list.
3. Click Stop to close the service.
4. Select Disabled from the Startup type list to prevent it from loading automatically the next time Windows starts.
5. Close the Services window when you're done.
Once it has been disabled, you will no-longer receive such messages.
Note that many firewalls also prevent this type of data from reaching your
computer in the first place, but it certainly can't hurt to turn off the service anyway.