Ping issue. Please help.

Someone wrote on another thread:

A broadband router is really just a dedicated computer with a built-in switch that serves a couple of basic functions: (1) to direct data packets to and from the PCs connected to it and the internet, and (2) allow the PCs hooked to it to communicate with eachother. The router uses NAT (Network Address Translation) to direct traffic from the internet that your PCs request to the correct machine. A side benefit of NAT is that it works as a firewall, not allowing your PCs to be seen from the internet-- only the router itself is visible, and it doesn't contain any data, so...

I have a question. I posted a question earlier about my computers not talking to each other at home. I have a Westell Versalink modem/4-port router in one with wireless capability. One PC is directly wired into one of the router ports. The other is connecting to the router through wireless card to access the dsl internet. The computer with the wireless card can ping everything but the other computer. It can see itself and the other computer under the local workgroup I set up to be able to share resources between the 2 computers. But it can't connect to the wired computer. It says the path was not found to it. The computer that is wired to the router can't ping anything except a default IP that someone told me to try. It's 127.0.0.1 That is the only thing it gets a reply from. So I guess before the 2 computers can talk to each other and share resources, I need to fix the ping issue with the wired computer. Anyone have any suggestions of why I can't ping and how I can fix this problem? I know if I can't ping anything by name, IP, or website that I will not be able to talk to the other computer. By the way, the wired computer can access the internet though. Is it a problem with my router or settings? Thanks for any help. Both machines are running Windows 2000 Professional. Please let me know if you need any more info.