speeding Login Scripts for win98 client

I just upgraded a NT 4.0 server to win2000 with
active directory. I have a script for windows 98
clients machines, for users to acess shares on the server. However, when a user logs in, the script runs but takes 30 seconds to finish, Why is it soslow? I used the net use command and everything was fine before the upgrade. How can I speed up the client login script?

It is a school district, in one domain,
I have domain controllers at each school under the global cataloging server. The shares are accessed locally at each school.