LAN connection not working

[#1]

Not sure if this is a software or hardware problem, particularly as we have had 4 power cuts today. I hadn't had my pc on until after the second cut and the problem was from the start, not caused by the power going off, so that may be a red herring. The pc that I normally use is connected to my router by cable, and suddenly today the LAN connection is not working. The problem seems to be in the pc, because I connected the router to a laptop using that cable, and it works. My normal pc is reporting in Device Manager that Network Adapter Intel 82566DM-2 Gigabit Network Connection has the yellow exclamation mark. I have tried re-installing that driver, but it hasn't made any difference.
Any suggestions please. Thanks

[#2]

Easiest thing to do would be to completely uninstall the driver / device and then reboot. Let the computer then detect it and prompt you to do whatever needs doing (it may autoinstall it instead). See if that fixes it. If it doesn't you could try a rollback but I would be more suspect that the thing has somehow fried itself.

[#3]

Thanks for that, 7up. I did what you suggested, but unfortunately it had no effect. I've solved the problem by buying and fitting a Gigabit Network Adapter PCIe Daughterboard, which was simple to install, and is working now. So far £9.95 well spent, though I would still like to find out what has gone wrong with the built-in adapter.
Thanks, and a belated happy new year

[#4]

As it turns out there is one irritating problem now. Although I can now access my router via the new Network Adapter card, when I boot up I get a message stating that new hardware has been found. As far as I can tell, it seems to mean the old NIC adapter.
When I went into Device Manager to uninstall that adapter, I got a warning message that uninstalling it may cause a problem at bootup, so I didn't uninstall it just in case. Is there a way to stop my pc doing this?
Thanks in advance

[#5]

Instead of uninstalling it just disable it instead. That should take care of it in theory.

[#6]

Done.
Thanks