Client XP Pro rejecting passwords

Archived from groups: microsoft.public.windowsxp.security_admin (More info?)

I have an XP Pro client machine on a SBS 2003 LAN that is now rejecting all
passwords as invalid. It denys login on both LAN and Local Machine. This is
for users as well as administrator logins.

The client has been working well. Another tech has now removed the machine
from AD on the server.

How can I gain access to the local machine admin account to reset the
passwords?

Thanks!