I installed the appropriate ethernet kext for my Dell Latitude D820 but when I go to the Network Setting in System Preferences, it says No IP Address and if I put one in... it still won't connect to the internet. I think I might have to configure everything by myself..because in Network Diagnostics, everything is failing. Oh well.
Any help would be appreciated.
EDIT: Solved using the D620_GMA950_LowRes Pack Ethernet Kext, found down below.