How to Disable Messenger Service on Windows XP
get rid of the annoying Windows Messenger pop-up ads:
1. Click on the Start button and open the Control Panel.
2. Open the Performance and Maintenance link and go to Administrative Tools.
3. Now double-click on Services, then choose Messenger.
4. Double-click Messenger and click Stop to stop the service.
5. Change the Startup Type to Disable and click Apply at the bottom.
6. Click OK to exit.