This problem began yesterday 12/18/2012. My WNDR3700 Netgear router suddenly will not allow my computer to connect. I have many computers here in my home as well as xbox, directv, several cell phones that all run off my connection through the Netgear router.
Running Windows 7, my "Network and Sharing Center" out of the blue disconnected from the internet. I hover on the icon and it shows me an "Unidentified Network". This is the only computer in the house that runs on a direct wired connection to the router. All the other devices connect and run fine. I then open the "diagnostic tool" and run it. I get a message saying "Local Area Connection doesn't have a valid IP configuration". After many resets and on/off cycles of all my equipment, I replaced the Ethernet wire with a new one. No better there. I then decided to swap it over to the wireless side. I installed the adapter and such. Now it tells me "Wireless Network Connection doesn't have a valid IP configuration." From what I've read this isn't ISP related and I would tend to agree since all my other devices connect just fine. Only this one computer started having issues. I hard wired from the DSL modem directly to the computer and it connects.
I cannot seem to find the problem between this one computer and the router.
