Find Windows 7 driver for Realtek RTL8111/8168/8411 PCI Express

Try here:

http://www.realtek.com.tw/downloads/downloadsView.aspx?Langid=1&PNid=13&PFid=5&Level=5&Conn=4&DownTypeID=3&GetDown=false

Otherwise, I would suggest you look up your motherboard model on the Gigabyte support website and download the ethernet driver from there.