Ethernet driver disappeared

I just bought a new motherboard 'not so new but new for me', an Asus B85-plus R2.0, when I got it it had an error in the ethernet driver, the cable works and is connected and the port lights up but there's no connection in the pc.

I had something else to do so my brother tried to fix it, it didn't work and when I wanted to try and update driver etc... the motherboard's "ethernet adapter" disappeared and I couldn't install it, I used Asus' website, troubleshooting gave me "driver is missing and it should be installed" and things like that, images should clear it.

so, can anyone help me on how to get the driver back, and please make resetting the computer the last option...