Network adapter dissapeared

Hi I have a studio hybrid .The internet stopped working now the network adapter is not in the devices list and is not being detected .I have restarted but it does not pick up that any network card is fitted ,which there is.

It is not a wireless card but wired ethernet.

The only way i can get internet is through a usb wireless dongle.

I cannot load any new drivers for the network card as it is not being detected at all

Any ideas from anyone would be appreciated