You can disable the messenger spam although doing so may result in Windows not being able to alert you to some conditions. A list of circumstances when Windows will use the Messenger service to pop up informative windows may include things like print spooler, anti-virus, and event logger status messages. 

NOTE: Click on the image to enlarge the screen shot. This will allow you to see the picture clearer. Then simply follow the steps.

1. Click Start->Control Panel 




2. Click Performance and Maintenance or Administrative Tools




3. Double click Services 




4. Scroll down and highlight "Messenger" 




5. Right-click the highlighted line and choose Properties. 




6. Click the STOP button. 




7. Select Disable or Manual in the Startup Type scroll bar 
8. Click OK