on windows xp: from a command prompt, type “gpupdate” then logout and log back in
on windows 2000: from a command prompt, type “secedit /refreshpolicy user_policy” after hitting enter type “secedit /refreshpolicy machine_policy” and hit enter. log out and log back in.
if they already have drives mapped, disconnect the mapped drives before updating policy. if you do not do this it will not remap the correct drives with the update.