Why would some pc's at one of our remote sites not be able to connect
to anything on the web?

Other machines are working fine on this subnet, just a couple are not.
The ones that don't do *not* have windows firewall on, etc. When doing
a tracert from them to somewhere like www.grc.com, it dies once it gets
to our core router.

Other machines that work on the same subnet will finish a tracert to
the same site, not getting killed at our router here.

I've tried updating the nic drivers, etc, etc, all to no avail.

Any suggestions, aside from fdisk, etc?