heads up this will also find a bad wire ..... maybe I can save you from buying a network card like I did ...when I forced it from 100kb to 1mb it said network cable unplugged .... I switched out the cable and now it works fine switched the setting back to auto find and I bet my motherboard Ethernet would work better now also with this new cable
in short TRY AT LEAST TWO CABLES BEFORE YOU BUY A NEW CARD ....your welcome