I can no longer log onto 4.0 NT Server

I just installed a DSL modem onto my home network and for some reason I can no longer log onto my server.

The set up is as follows:
Server = NT 4.0 with it’s own IP etc for DSL.
Workstations = Win98 with IP for DSL. They all connect to a 5 port hub.

I can ping the server but when I try to log on it says that there is no domain available for validating my password. I was able to log onto the server before setting up the DSL anc configuring the new IP addresses.

Any suggestions?