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->Programs->Administrative Tools->Services

2. Scroll down and highlight "Messenger" 

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

4. Click the STOP button. 

5. Select Disable or Manual in the Startup Type scroll bar 

6. Click OK