right click disabled on start menu

many moons ago i used one of the many xp tweaking programs and i set the disable right click on the start menu.
i no longer have any tweak programs installed and i cant remember which one i used to disable it.
i was hoping someone can tell me which registry key i need to edit to re enable the right click feature for the start menu
i would rather edit the registry than go through installing the xp tweaking programs to find the relevant setting to change.

any help will be much appreciated, thanks peeps :)