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I have a Windows XP SP2 desktop PC. It connects to the internet with a LAN cable (there's a wireless router for my laptop in between). The problem should be software because:

  • when i tried connecting the same LAN cable to my laptop it works
  • when i plugin the LAN cable (onboard) the green light is on and the orange light flickers
  • when i tried the other cable (that feeds the wireless router) i have the same problem
  • it worked a few days ago, nothing specific changed

I tried removing the ethernet card from the device manager, and windows automatically reinstalled it.

What could cause this? What can I try?

share|improve this question

You could try:

  • Checking that ipconfig /all shows MAC & other info. If not suspect HW.
  • Using XP's Network Manager to diagnose the problem
  • booting from a live CD to see if it sees the LAN
share|improve this answer
I tried this. MAC is ok. I installed Network Monitor (is that the one you mean? otherwise more info please). If I get it right it sends a request to the DHCP server (to obtain an IP i guess) but I don't see a response returning. Also, I cannot startup msconfig. Any ideas? – Koen Jan 3 '11 at 19:36
Also I'm not sure whether my DHCP server should be on the wifi router or on the computer itself... – Koen Jan 3 '11 at 19:37
I meant XP's built-in network repair tool. There's also a Diagnostic tool you can download. Normally your router provides DHCP service. – RedGrittyBrick Jan 3 '11 at 22:15
I tried that and the log says: status of the network adapter is not good. I guess if the light still indicates green it would work or could the hardware still be broken? I'll try the live CD now... – Koen Jan 4 '11 at 20:39

When your PC can connect by both wireless and wires it can get very confused.

First: ensure that you're not connected to any wireless network.

Then: you can diagnose your Ethernet base-T cable issues.

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