Simons correct Reanne, its missing or has the incorrect driver for one unidentified device and the ethernet controller.
Try uninstalling both of them from inside device manager and reboot your pc, it may find and install the correct one automatically.
If that doesnt work do you know if you have a seperate ethernet PCI card or is it an onboard one ?
One easy way to tell without opening the pc up is if its in one of the horizontal slots at the back of the case its a PCI card but if its bundled in with the USB and other connections at the top then its an onboard one.
If its an onboard one then the drivers should be on the motherboard installation cd that you should have got with the pc.
If you havent got one then if you can let us know the make and model of your pc we may be able to find the drivers for you