I'm running Windows 7 using a DSL line connected via ethernet. I've lost my internet connection, and Windows 7 Diagnostics reports that there might be a problem with the Local Area Connection Adapter driver. Unfortunately, it doesn't say what the problem might be or what to do about it. AT&T has verified that the problem isn't with the DSL line or the modem, and for good measure I bought a new ethernet cable. To make a long story short, I waited too long before considering a System Restore and no longer have restore points available from before this problem started, which was eight days ago. I've visited the Device Manager and the ethernet adapter is enabled and working properly. I would think this should be the last word, but it obviously isn't since I remain unconnected. I have no idea what to do next. Anyone?
If you have an IP that doesn't start with 169 then you're being assigned an IP by your router/modem, which is a good sign.
Try logging onto your modem/routers web config page; The address is the same as your Default Gateway. There should be a page on the modem/router that displays connection status, check to make sure there's an active connection.
If you're not able to get on your modem/router, then the problem could either be that your modem isn't acting as a DHCP thus isn't handing out IP addresses, or that there's an issue with something on your PC.
I'm sorry I'm not able to do these things that you mention as I write this. I only have one computer and I am now at the library. I do remember being unable to access the modem as directed by my DSL tech support. My modem is a Speedstream 4100. When AT&T sent a technician to my apartment he was able to connect to the internet with his laptop using my modem and cable, so there's obviously an issue with the computer.