"An error occurred that requires the assistance of the Helpdesk" or something similar..
The system was getting an IP address from the modem, I could surf to 192.168.1.254 and get to the "login page" on the modem, and no other problems were obvious. After a quick Google search on another machine I found http://dslinstallation.bellsouth.net. I used that site to register for a user ID and password. Then I logged into the modem with that login information and voila.. Internet.
Bellsouth/AT&T installation CDs remain useless. They could at least provide meaningful error messages.