Problem with network

Here’s the problem:
I cant setup my network (2 PCs conected via UTP cable, one shares IC to another)
But worse than that my network card seems to be blocked somehow. I’m logged in as Administrator and cant complete any of the following: change LAN properties, complete Network setup wizard, uninstall my network card driver…

Network card is onboard nVidia nForce networking controller

What should i do? Is it probably a hardware problem?

Thanks for help