Unable to connect to the internet

I have three computers connected to a Lynksys etherfast cable/DSL firewall router. Two of them are working find. All ports in the router work fine and network cables are fine as well.

I have a p166 computer running windows 98SE with 128 MB of RAM. Also, this computer has a netgear fa311/312 PCI Network adapter, TCP/IP is configure to auto detect IP address. The adapter lights and router lights are turned on and I am not able to connect to the internet. What could be the cause?

I also tried the network adpters from the other working computers and I tried going back to windows 98 from a previous installation of windows 2000 Profesional but it still does not work. Any suggestion?