I was trying to capture localhost traffic with Ethereal, which doesn't work without re-routing localhost traffic to your router gateway. I didn't get the route command quite right, and messed up my routing table. I typed route -f to clear the routing table and rebooted, but when I finished rebooting, the routing table wasn't restored to its original state. I didn't use the -p parameter, so none of my changes should have persisted after a reboot.
What can I do to restore the routing table to its default routes?
Turns out that because I had setup the IPv4 settings for the NIC to use static values, Windows didn't completely rebuild the routing table when I rebooted. I changed the NIC to get its address from the DHCP server, which rebuilt the routing table, then I set it back to static values again and rebooted. The routing table is fine now.