If you're just looking for the network driver, try downloading the LAN driver off this site.

If it's not installing check to make sure it's being seen by the computer. Click on your start menu and right click on "Computer" (Vista/7) / "My Computer" (XP) and click "Manage". From here click on "Device Manager" and see if the network adapter is listed at all, or if there's anything with a question mark beside it. If there is then try and find out what the device is by right clicking on it and selecting "Properties", under the details tab you can select "Hardware Ids" and find a 4 digit code that comes after VEN_ and before the &. Go