Windows won't detect network adapter.

mattius1989 · 20 May 2015 at 18:25

Evening all.

(this is for the on motherboard ethernet port)

I came home last night to find my computer had turned itself on and was claiming a hardware change and windows need to be revalidated.

I tried it but realised my Internet was down (red cross symbol in bottom right). Checked all my wires and couldn't resolve the issue. Having inspected the device manager, there doesn't appear to be a network adapter being detected and there is nothing in "other/unknown devices".

I've tried a few resets, unplug, cmos clearances and checked the bios for the network adapter being enabled (it is) but no joy so far. Does this sound familiar to anyone? Somebody on an old toms hardware post suggested a similar instance due to poor weather but I'm on a network so surely that would have stopped at the cable box? The orange light is still on the ethernet port.

I'm tempted to just order a new pci-e network card unless somebody has a solution? Everything is working fine. I've checked for viruses too.

Thanks in advance.

asim18 · 20 May 2015 at 21:03

Go into device manager and see if it's there. It should tell you if there's any conflicts etc. There's a button at the top to "scan for hardware changes" press that too.

mattius1989 · 20 May 2015 at 21:59

Thanks, but I've already checked the device manager and there's nothing in there that it could be. Not even any unknown devices.

Rainmaker · 20 May 2015 at 23:46

Do you have, or can you download from another machine, a Linux live USB/DVD? At least that way you could check whether the port was 'dead' or it was definitely a Windows issue.

martian1 · 21 May 2015 at 04:30

Ok i have just had a similar experience myself not sure when it started but i had a red cross on connection symbol in right corner yet still had internet, after reading up a little i was advised to uninstall the realtek network adaptor and let windows reinstall it.
Windows did not re install it and internet was lost..proper lost! I tried allsorts to get it working yet windows just stated there is a problem with the realtek ethernet adapter error 31 windows cannot install the device!
I bought a pci nework card which refused to install as well so basically i began to think windows is porked. Next test i had an oldish clone backup of windows which i did not want to resort too as it was around 6 months old and i had new software installed etc
Nevertheless i had little choice so i plugged the clone in i had created and everthing was back the internet worked i could see the realtek network adaptor etc unfortunately i think you might be in the same boat hope you have a backup. The worrying thing is how the hell did this happen i suspect a windows update!

mattius1989 · 21 May 2015 at 11:03

I've just ordered a pci express network card. I'll try that out and see how it goes. If that doesn't resolve the issue, I'll try a format.

Steve2000 · 21 May 2015 at 12:30

Have you had any Windows updates recently? Try uninstalling them if so.

cuke2u · 22 May 2015 at 13:55

Or a system restore before the point at which the issue occurred?

ginjaninja · 22 May 2015 at 18:28

windows redetecting motherboard network cards is sometimes after a bios update..but then i guess youd know if that was the case.

the device manager has the option view hidden devices......if my settings changed whilst out especially to do with network i'd do a paranoid check of rootkits, viruses etc....check the bios still has the network enabled...

mattius1989 · 26 May 2015 at 10:24

Picked up a pci-e network card at the weekend and it's working great. Not sure what happened with the onboard but I'll consider it broken. I'll be sure to run a few scanners to be safe.

Thank you all for your help.

Sauced Apples · 29 May 2015 at 20:22

If the network adapter for the original port is showing in device manager then you could go into the properties of that adapter, select the hardware ID, copy and paste it into Google, download the driver then uninstall adapter.

Then simply reinstall. Not sure if you tried this but it seems odd to not troubleshoot drivers before replacing hardware?

mattius1989 · 29 May 2015 at 21:06

Unfortunately the onboard network adapter has disappeared from existence as far as the device manager is concerned.

Sauced Apples · 29 May 2015 at 21:11

Ok, did you try finding the driver and installing anyway? If it's getting power then it should reinstall if the drivers are correct.

drakie · 5 Jun 2015 at 01:49

Go to the manufacturer's website and try to find the driver. It's your best option.

ginjaninja · 5 Jun 2015 at 12:59

good that a new card worked...but nics dont just go missing...drivers wont help if windows cant see the hardware...

if the nic is enabled in the bios, and no unaccounted for devices show in device manager (even with show hidden enabled), then i would not rest on your laurels.

If you are reasonably technically competent, i would be looking to get to the bottom of it..perhaps with a fresh build...i couldnt sleep at night... :-)

Sauced Apples · 5 Jun 2015 at 14:40

Windows may not recognize the hardware, drivers are always the first port of call, no matter how bleak their outlook is.

bledd · 5 Jun 2015 at 16:32

Had any lightning strikes recently?

My mum's pc took a hit, the crab logo on the realtek chip had an arm missing

Needless to say, LAN didn't work very well.

First thing I'd do in your position is try a live Linux disc, like Ubuntu.