Win2000 Pro disappears from browse list

I recently converted a Win98 SE machine to Win2000 Pro. Now it is not visible to other network machines. I can ping it by IP address and it sees the WinNT 4.5 SBServer and is able to access files on the server. It cannot be seen on the server’s browse list or on any other machine on the network. All other clients are Win98 machines. It cannot print to a shared printer on another Win98 machine on the network. It does not see the shared printer, only the the Win98 machine on its own browse list. I can ping any and all machines on the network from the Win2000 machine but I cannot access any shares other than on the server. The NETBIOS name is activated on this computer but it is virtually invisible. What gives and how do I correct it?