Here is something I found that should disable that popup from coming up:
1. Click Start, click Run, type regedit, and then press ENTER.
2. Navigate to the following subkey:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
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 regedit. Log off Windows, and then log back on.
These steps disable all Notification Area balloon tips for this user. Hope that works!