Windows 98 not recognized on NT Network

Here's my problem. I have a win98 machine on an NT network. The 98 machine can access files on the server, but cannot be seen in network neighborhood by any nt machines. When I go into server manager on the nt server, the 98 machine is dimmed. When I try to access it, I get the message "the network path could not be found". But I can browse the network through network neigborhood with the 98 machine and see the nt machines. I cannot connect to the exchange server either. What am I missing? Help!