Asus M5A78l-m Ethernet problem

[Del_Boy]

Hi all, I'm having this prob where that pesky yellow exclamation mark is present on the Internet sign upon windows/desktop start, i have to manually connect to the Internet by going into device manger network adapters disabled then enable the driver and yellow thingy goes away and i can then surf but the process is now getting very tedious, Ive tried unistalling and re-installing drivers, updating bios, updating drivers, different drivers, nothing seems to work, can anyone help please, for the record its definitely the drivers aren't starting up when windows starts how do i change this ?????