I'm working on a friend's computer (Win 98) who lost her inet access. I've hooked it up to my Linksys broadband router. I can ping itself, I can ping 127.0.0.1, but I can't ping the router or any other machines on my network. I can't ping her machine from others on the network. But it DOES get configuration from the router's DHCP. I've also tried it with a static ip, same results. I've tried two different nics, two different cables, all of which work fine on other machines, but the behavior is always the same. I've run NAV and Ad-aware with the latest defs and everythings clean.

Any ideas?

Try disabling any software firewalls(temporarily) to make sure it isn't locked down. Since you can ping localhost(127.0.0.1) this tells me that tcp/ip seems to be working properly, since you are getting a valid IP from DHCP it would seem that the card is communicating with the router.
Might try resetting the TCP/IP stack, maybe flush DNS as well

Does resetting the tcp/ip stack mean just removing and re-installing tcp/ip? There are other services using it (aol ) but that was going to be my next step, uninstalling all networking and rebuild it from scratch.

DNS is set to disabled in the tcp/ip properties and it looks like it's being set from the DHCP server.

DNS is pretty much required unless you remember IP addresses for sites.

Does http://12.96.164.87 work, for example? (that's TechSpot)

I meant DNS is disabled for the tcp/ip protocol bound to the nic in Control Panel. When I display ipconfig, the dns' listed are the same as those setup in my broadband router/gateway. So it does have dns settings, but nothing is getting out. In IE I just get a "The page cannot be displayed" message for any site, including http://12.96.164.87

Go to Start>Run, type netsh int ip reset resetlog.txt

OK, I got it going. I removed all networking protocols, services & adapters and re-installed. There were also some strange issues caused by Zone Alarm being removed.

Thanks for the help and suggestions!