Windows XP default speed of the Start Menu is very slow. You can fix that by editing a Registry Key.
1. Go to Start> Run, then type in: regedit Press [Enter] on your keyboard.
2. Navigate to the following key: HKEY_CURRENT_USER \ Control Panel \ Desktop \ MenuShowDelay
3. By default, the value is 400. Change this to a smaller value (like 0) to speed it up.
Note: If your still experiencing a slow speed of the Start Menu, even after using the above tip, then you might try the following:
4. Navigate to Display Properties> Appearance> Advanced
5. Turn off the option titled Show menu shadow . You will get much better overall performance.