I have two machines connected to a router to share cable modem internet access. Everything works fine, but now we want to take out the netgear router since there is now only one machine. I disconnected the cables and connected the cable modem directly to the computer via cat5 cable. Now when I try to access the internet, It gives me dns error. I did a release/renew, but it didn't help. Is there a step that I skipped? is there a setting that I needed to change so that it now works directly from the cable modem as opposed to from the router? Also what's the difference between a router and a hub/switch?

Thanks