Network Cable Unplugged

I am having problems with my network adapter, it is a onboard nvidia nforced 10/100/1000 network adapter on my m3n78-em motherboard.

I recently reformatted my harddrive and when I installed the drivers for my motherboard it said my network cable was unplugged and the message keeps on popping up, The most irratating thing is that it was working previously…

I have several pc’s and I haven’t had a problem like this before, it is a new pc and I need it for work.