Windows 7 - default gateway issue

[shane_c]

We purchased a Dell Inspiron 560 desktop about 3 months ago. It has Windows 7 and has been working great for the first 2 months. The last month I have been having intermittent issues getting online. It can’t pick up a network connection on the ‘home network’ so goes to a ‘public network’ and doesn’t find anything. If I run a diagnostic it says network cable unplugged even though it’s not. If I go into ipconfig there is no default gateway showing. I don’t have a router, it’s direct from the modem to computer.

I have made several calls to my provider and they say everything looks good on their end but they came out and gave me a new modem just incase there was an issue with it (but it wasn’t). I called Dell several times. We reinstalled the drivers, tried to do a system restore but got an error, sometimes when you load in safe mode with networking it connects but other times it doesn’t. If it does connect in safe mode and I restart it will connect in normal mode. They think it was a conflict between Norton 360 but I uninstalled that and still couldn’t get online. Dell says the next step is to do a PC restore but I don’t want to do that because I’d have to back everything up and start fresh again. I looked on the computer this morning and it said there is a Service pack 1 update available so I installed that but don’t know if it will make any difference. I did some searching online and it seems to be a common problem with Windows 7 but I haven’t really found any way to fix it. Any ideas?

[photon]

Could be a problem with the network cable or the network card too, I've never seen anything like this on Windows 7.

[psicodude]

you say there is no default gateway, does that mean you are getting an IP address that starts with 169.x.x.x? If so, you aren't getting an IP address from Telus which is most likely cable related.

[sclitheroe]

If it says network cable unplugged, it's almost certainly a hardware issue. This indicates that the network port is either not detecting link state correctly, or is in fact not getting link at all, both of which point to physical issues with the ethernet transceiver or cable (you replaced the modem, so we know its not likely that).

If the cable and/or port was good, you'd see errors indicating limited or no internet connectivity, which means you have link, but not a routable IP address.

You could try going into the properties of the network card (Control Panel -> Network and Sharing -> Change Adapter Settings -> right click on network connection -> Properties -> Configure, and then look for link speed and duplex) and setting the link speed/duplex to 10 megabits half duplex, which is the lowest common denominator setting, and see if that helps. If the transceiver or cable is flaky, often this will at least get you working again until you get it fixed.

[oilyfan]

I am going to bet some good money it is the network cable