SYMPTOMS
When you install Windows NT Advanced Server or Windows NT on a new computer
that you want to add to a domain, if you use a machine name that already
exists on the network, Setup will continue normally up to the point where
it starts the network. At this point, the following error message appears:
A duplicate name exists on the network. This error prevented the
network from starting. As a result, you will be unable to join a
domain at the present time.
Because of this error, you are unable to join the domain you planned on
joining. You will be prompted with a dialog box giving you the option of
starting your own domain, or joining another domain. If you start you own
domain, there is no way to join the existing domain at a later date. If you
abort this dialog box, it completely aborts Setup.