pc is getting ip address of all 0's, router is working ok with other computers, does all 0's for an ip usually mean hardware problem or tcp/ip problem?

It means you don't have an IP. I assume that you have the client set to 'obtain IP automatically'. The type of client would help. I'm assuming this is Win95 or NT, otherwise you should get an IP in the 169.254.x.x range. Assuming it is set to obtain automatically, then it is trying to contact a DHCP server for an address, in your case your router is probably performing this function. If the client can't contact the router, then it won't get an IP. This could be a hardware problem, cabling problem, driver problem. What OS are you using? ARe you set to Obtain Automatically. Have you tried setting a static IP just to see if the NIC and cabling works? That would be a good start.

Try conecting to the router. From a CMD window, try pinging the router. It should tell you in the manual that the IP for the router is. For SMC's, I know it is 192.168.2.1. If you get ping reply's, your communication to the router is fine, and you have a different problem. Check to make sure that DHCP is set correctly for the router configuration, and also make sure you did not set a static IP in your network settings in Control Panel. You can also do an ipconfig /release to release an IP and ipconfig /renew to get a new one. This is helpful when trying to refresh the IP information.

He's not going to ping anything if his IP is 0.0.0.0.

you are not obtaining an ip address so either the DHCP server is not giving you one (if all other computers can obtain one probably not DHCP Server) make sure the cable is not a crossover cable if it is get a patch cable. last thing is bad NIC or worng configuration. try pinging 127.0.0.1 thats the loop back with or with out and ip address you should be able to ping that.