Network problem

In my company there is Windows 2000 sever, 4 Windows 2000
and a windows 98 operating system.I had connected in LAN.

The IP address for 4 win 2000 is;
192.168.100.27 (Username:Anand)
192.168.100.29 (Username:Shashi)
192.168.100.31 (Username:Raja)
192.168.100.33 (Username:Richa)
The IP address for a Win 98 is;
192.168.100.25 (Username:Ashok)
The IP address for a Win 98 is;
192.168.100.1

Domain name :Seaonics

My problem is win 98 system is not connecting in
lan and in that system there is a internet connection.
When i login it reported that "Network error occurs".
In Anand System it is not connected in domain.
Please clear my doubt.