Turn Off the Messenger
Windows Messenger services use NetBios, a standard protocol that enables communication among systems on a network. You can deactivate NetBios in Windows NT and Windows 2000 by a series of commands that block the NetBIOS ports (ports 135-139).
First, go to Start, Settings, Control Panel, Administrative Tools, and Services. Next, select Messenger from the list and right-click; then select Properties. Last, select the Stop button and then Startup Type and finally Disable.
Windows XP users wishing to turn off Windows Messenger service should go to Start, Control Panel, Performance and Maintenance and select Administrative Tools.
Next, follow the same steps as you would with 2000 and select Messenger from the list. Right-click and select Properties. Select the Stop button, choose Startup Type, and then pick Disable.