Here's how to turn them off in five simple steps:
To Disable The Notification Area Balloon Tips
Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
1. Click Start, click Run, type regedit, and then press ENTER.
2. Navigate to the following subkey:
3. Right-click the right pane, create a new DWORD value, and then name it EnableBalloonTips.
4. Double-click this new entry, and then give it a hexadecimal value of 0.
5. Quit Registry Editor. Log off Windows, and then log back on.