windows firewall cannot display settings

the goal: to dismantle the old nt pdc and add the server role of domain controller to our new windows 2003 server. Added the dns and active directory with only minor hiccups over computer name. Have setup users and computers in ad, but computers cannot join the domain. Thought perhaps the firewall was to blame, but when I try to turn it off i get the message that due to an unknown error, windows cannot display windows firewall settings. any help is greatly appreciated!!