DNS Troubleshooting

[Bob]

I support a two PC peer to peer LAN that is connected to
the internet via a Caymen DSL/router. Both PCs are
running WP XP Pro. Both PCs have been working fine with
internet connectivity until recently when one of the two
quit working. The tcp/ip configurations have been
verified to be the same on both PCs. The defective PC
can ping the default gateway, the IPs of the DNSs, or any
other valid IP address outside the LAN, but can not ping
an IP name such as www.yahoo.com. Both PCs can ping each
other. The defective PC can not access the internet via
the browser or email but can ping any valid IP address.

We have restored the base TCP/IP files using "netsh int
ip reset resetlog.txt". Both the WIN XP and Norton
firewalls are turned off. We have compared info from
ipconfig /all from both PCs with no differences. We have
checked the connection setup on the browser.

I thinking of restoring the PC to a date when the the
connection was working.

Any other ideas?