Hi, I have recently reformatted my hard drive and found a yellow question mark against Ethernet controller. It has an error code 28 and says that no drivers are installed. I have searched the internet for the driver without success. Please can anyone help?
Motherboard is Gigabyte GA-K8NSC-939.

Did you try the Gigabyte download site for your board?

GIGABYTE - Support&Download - Motherboard - Driver - GA-K8NSC-939

Yes I have been to the Gigabyte download site and I have installed all the drivers in sequence but the driver for the Lan will not install and brings up a message that says, This installation package is not supported by this processor type.

That's a typical error you get when you try to install 64-bit drivers onto a machine running a 32-bit OS. Did you select the right driver? The description of the driver listed under "LAN" is a bit confusing, but it says 64-bit.

Look under Chipset. The first item says, "Included LAN driver".