Use at your own RISK! Messing with the registry can ruin a perfectly bad computer!
To disable balloon tips in the notification area (Right side of the task bar):
[HKEY_CURRENT_USER \Software \Microsoft \Windows \CurrentVersion \Explorer \Advanced]
EnableBalloonTips = 0
More Info MS KB Q279771
More Info MS KB Q307729
To disable "Show popup description for folder and desktop items" (Folder Options):
[HKEY_CURRENT_USER \Software \Microsoft \Windows \CurrentVersion \Explorer \Advanced]
ShowInfoTip = 0
To disable tooltip for folders:
[HKEY_CURRENT_USER \Software \Microsoft \Windows \CurrentVersion \Explorer \Advanced]
FolderContentsInfoTip = 0
To disable tooltips for the start button:
[HKEY_CURRENT_USER \Software \Microsoft \Windows \CurrentVersion \Explorer \Advanced]
StartButtonBalloonTip = 0
To disable tooltips for the start menu:
[HKEY_CURRENT_USER \Software \Microsoft \Windows \CurrentVersion \Policies \Explorer]
NoSMBalloonTip = 1
