TCP\IP Problem

I’m mounting a red of 5 computer running win95 and a the server is running win2000
from the server I see each of thers PC by doing a ping but I can’t see the server with this way and eather from the explore, I assing and IP adress to each PC but I don’t see the server(is using win200) fron the PC or fron Itself in explore it gave the followin error “NETWORK DATAGRAM SEND FAILED, ERROR X23” and “FAILED TO REGISTER STATION NAME ERROR OX23″ I remove the TCP/IP protocol and reinstall it againg andgive me tha same error Q:”WHAT CAUSE THIS SITUATION”