I was able to stop xdm from running at startup by: 1) running Debian setup from the CD and pressing ALT + F2 on the first screen 2) mounted my root drive so I could move and copy files 3) moved /etc/init.d/xdm to my home directory for temporary storage 4) unmounted the root drive 5) rebooted the machine 6) reconfigured X using XF86Setup 7) copied the xdm file back to /etc/init.d
Thanks for your help, Steve T.
