Workstation not accessing internet

We have a network of 10 machines accessing the internet modem through a celer access unit connected to the hub.
Using Netscape communicator 4.75 as browser all network machines have been set up identically and nine are working fine.
Have tried reinstalling netscape and network driver (Netgear FA310TX).
Network machines automatically find IP addresses (found from Celer Access Unit)
Problem is:- one machine refuses to access the internet although it recognises all other machines in the network (LAN).
It was working fine until some maintainance was conducted on the Celer Access unit to check settings. All settings were returned to original.