Domain Controller not found

We have DNS and WINS on headquarter and one BDC (also run DHCP and Exchange 5.5) on each remote office. One remote office have the problem of “Domain Controller not found” when users (WIN95B or C) tried to change their passwords.

All servers are NT4.0 with SP5. I can see all other servers from that BDC. I suspect it maybe name resolution issue but I don’t know where to start troubleshooting. Thanks for help.

Tony