To whoever it might help. Searching for a solution, because my NW 6.5
server would not boot anymore I only could find that the problem is that
command.com cannot be loaded. Reinstall should be the only sollution.
Removing a replica and the server takes quite a while when the server is down.

Boot the server with a win98 flop
cd nwserver

and the server boots :-)))
you can choose than a conveniant time to reinstall the server

in dsrepair -a on the crashed server its a lot easyer to remove the replica
and than nds. Bring the server down and remove the server objects and
related objects which was easyer for me in nwadmin.

Good luck and it would please me if you would send me an email if this info
is usefull to you.