Error when I try to add domain users to local group

[Shawn]

When I try to add domain users to the local admin group I
get the following error "the specified domain either does
not exist or could not be contacted"

However I was able to leave and join the domain on the
local PC, Log on to the domain from the workstation, and
view the domain users from the workstation.

I am having this problem on other workstations also so it
appears to be a server problem

Configuration
Workstations Windows 2000 Pro SP4
Server SBS 2000 (running just Exchange) ISA was installed
on it, but now it has been uninstalled.

 

[Marina Roos]

Why for heavens sake did you uninstall ISA???

Does the ipconfig/all from the clients show that everything is pointing to
your server-IP? How many nics in the server?
Make sure you don't connect to a share on the server before you join a
client. Make sure you're logged into the domain as administrator on the
client to be able to make the domain users member of the local
administrators group.
Check out www.smallbizserver.net and the
microsoft.public.backoffice.smallbiz2000 newsgroup.

Marina