Hello and welcome to the forum.
In the offical nVidia site the drivers there found are only for XP and Vista I even downloaded from official GIGABYTE site and that didnt help too.
Very often if not almost always the Vista drivers will work for Windows 7, you may need to install them using compatibility mode though. Just right click the installer (.msi or exe) and choose properties and select the compatibility tab and choose Vista see if that works.
The network adapter is found and works properly but the ethernet controller doesnt have a driver
What does that mean, seems contradictory. If you are having an issue and installing the drivers that you have found from either Nvidia or Gigabyte using compatibility modes doesn't...