Speeding up the Start Menu (Windows XP)
Most of us are experiencing delay (slow) opening the StartMenu when we click over it to open the All programs, and others features whichare attached to it. We can speed up this by tweaking the registry withoutaffecting to the operating system. This default speed can be adjusted with aquick Registry modification.
To do this, go click run – type regedit, the registry editor window will open, go to HKEY_CURRENT_USER
Double click MenuShowDelay to open, you’ll notice that thevalue is 400, now set it to 0 (zero), click OK and close the registry editor,now check the speed of the whether it has taken effect or not. The Start MenuSpeed should have been changed to full speed by now.
For better reference, I've included the graphical representation to perform this tweak step by step:
Try this yourself and enjoy the speed of the Start Menu in windows XPwithout spending a penny or installing additional applications. Good Luck.