PC can no longer connect properly to the internet?

My GF told me her computer's firefox wasn't working, so I looked at it and found that Internet Explorer and a few other internet programs also weren't working. It doesn't return any sort of server not found error on the browsers, if I click a link it just seems to do absolutely nothing, it doesn't even attempt to load the site. I did a full system scan for viruses and malware and found nothing. I also verified that the firewall was not blocking connections.

Windows seems to indicate it's connected to the internet. It's on a wired connection to my router. I tried resetting the router with no change. I know the router and modem work because I am also connected to it via WiFi.

I looked in the device manager and I saw under network adapters that the Microsoft ISATAP and Microsoft Teredo Tunneling Adapter both had a Code 10 Cannot Start error. I have no idea what those are or if they have anything to do with my connectivity, but the actual main network adapter reports it's working fine.

Any clues on what to try next? She has Windows 7 Pro SP1

matts6887 said:

The easiest thing to try first; is to do is to click start, accessories, then right click command prompt and select run as administrator. Once you do that type ipconfig /release. Once it releases the internet adapter; do a ipconfig /renew. That might resolve the issue. Also, assuming you have a router; I would try to do a power cycle of both the modem and router. Unplug both the router and modem for about a minute or so; then plug the modem back in first and let that boot fully; then plug the router back in and let that boot fully and see if that does anything for ya. Try one or both of those and see if it works out for ya. If not post back here and we can go from there.

The reboot did not work, and the ipconfig did not work either.

I do believe however that it is a router issue. The ethernet light is blinking orange instead of green, which I assume means there's an issue with it. I tried using another ethernet cable, even tried connecting it through all 4 outputs but all of them give the same issue. My other computer, my Roku, and my PS3 all are connecting fine to this router but they are wireless.

It's an Arris router/modem combo (one box) provided by my cable company. Any idea how I go about troubleshooting my router's wired ethernet issues?