Getting IP from router but can’t ping

I have added a Linksys ADLS Router to my home network of 3 computers. One of the computers is getting an IP address from the router but can’t ping anything on the home network or web and can’t be seen by the other computers on the network. It and one of the other computers (that are working) are running Windows ME. I have uninstalled DUN and TCP/IP, replaced the NIC, checked the cables and reinstalled Windows. Ideas anyone?