Open the Registry Editor click on the Start button on your taskbar, then click on Run and type "regedit" and click on OK to start the regedit utility.
Expand HKEY_CURRENT_USER\Software\Microsoft\Windows\ CurrentVersion\Explorer\Advanced
Modify or create, "EnableBalloonTips" and set the Value to "0". To restore set the Value to "1".
hope this helps
timbo