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I'm dual booting on my machine with Fedora 13 and Windows 2008 R2. Everything is hunky dory in Linux. Last night I restart into windows (to play some call of duty, and yes I know I can get that running under wine but that's a different topic altogether). Windows is telling me my network cable is unplugged. It clearly isn't because everything works if I restart back into fedora.

I tried hooking a different cable just in case, tried booting into safe mode with networking, tried uninstalling and updating the network drivers (it is a Realtek PCIe GBE nic) still the same thing. Recently (like in the last 2 weeks) I got a second display and a gigabit switch. I tried hooking in my old 100mb one and just the old display thinking maybe it is a configuration issue. No luck.

I noticed that the light on the nic always glows a steady green when I'm in Linux or booting into windows. A few seconds before getting the windows login screen it disappears never to be seen again.

At this stage I'm thinking it is either a virus or a windows update gone bad. Anybody seen this before?

My setup: Asus M4A89TD Pro modo, Athlon X4 630, ATI 4850.

Edit: Some more details: After I reinstall the drivers (using the ones obtained from vendor) the green light comes on for a split second and then dies again. During the boot sequence the last driver to load is ClassPNP. There is around 10 seconds silence then disk activity. The light dies after around 5 seconds of disk activity and ~2 seconds before the login screen.

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2 Answers

I have seen malware do it by failing to patch a network driver properly. If they modify the inf file relevant to your hardware the reinstall will fail to fix it. You could try getting latest drivers from the vendor and installing from a specific location. Another possibility - does your gigabit switch have PoE? It might be goofing with the card during init(on windows). If you want to try and see what is killing the card, you could try going safe mode with networking with a mirror setup behind the PC so you can see what "just loaded" when the card drops.

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What is a mirror setup? The drop happens after it finished loading everything. There is a ~5 second pause between the last line and the screen showing the login. The drop happens mid way through that pause. –  Pavel Nov 27 '10 at 16:20
    
A physical mirror so you can see exactly when the led goes out, but it drops after everything loads I don't know –  hbdgaf Nov 27 '10 at 16:25
    
ah, I was thinking it must be a term for something. I'm actually running caseless with the mobo turned 90 degrees so I can see the back while looking at the monitor without problems. –  Pavel Nov 27 '10 at 16:58
    
As far as I know there is no PoE on my card. –  Pavel Nov 27 '10 at 17:07
    
that's the point..if it's on the switch does it break something –  hbdgaf Nov 27 '10 at 19:06
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So I left this install alone for a couple of weeks. Came back today, booted into Windows and vola! Internet working without any problems! I have not changed any hardware and I haven't touched the OS for a few weeks.

Thanks everyone for the help though. I guess this one will have to go down into history books as an unsolved mystery.

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