no internet access either via wireless ("no available networks") or via cable

Either something is wrong with your router's setup, the router is messed up, your modem, or your service. If it's one of the first two, it's your problem. If it's one of the last two, you'll have to contact your ISP about it. Did it work properly and then suddenly stop? If yes, try recycling the power on the router (unplug, count a slow 10 then plug it back in and wait until it's done booting). If that doesn't work, reset the router to factory defaults and set it up again. If that doesn't work, plug the modem directly into the network interface on your computer. If that doesn't work, call your provider.