Hello, my adapter is onboard it worked fine reinstalled windows and its not detected i plug in ethernet and it lights up windows wont detect it though it is a dell xps 310 2x1gb ram 2x 1.86ghz dual core intel processor and a nvida 5xx running windows home premium had to reinstall due to being hacked
it looks like you reinstalled windows and you will need to re-install Network Drivers also. you should have Drivers CD for your Dell (If they have provided one) with your system OS cd. run Drivers CD and you can install Network Adaptopr drivers from there. This CD also contains your Audio, Graphics card, Modem etc drivers.
If you dont have CD then you can go to Dell website and download necessary drivers using your System Tag provided from Dell or by Model number.