The Start Menu take a quite a while to display the list of programs installed. In order to get Windows XP to display the list faster, you will have to edit some registry settings. Remember to back up your regitry before making any changes.

To speed up, goto Start > Run and type regedit. This will open the registry window. Then navigate to the following key: HKEY_CURRENT_USER\Control Panel\Desktop. Scroll down in the Right panel and double click on "menushowdelay". In the Value Data box, change the default value for the menu speed from 400 to a lesser number, such as 1 or even 0. Click OK You should now find a significant increase in the startmenu speed.