Dell :: No Ethernet Controller Driver / Win XP On Optiplex GX270

I installed a fresh Windows XP Pro on my Optiplex gx270 last week. Everything was fine but now I cannot get an internet connection. I followed all the steps on the dell support web site for the windows reinstall, putting all the drivers on in the correct order, all from my original resource CD. Then downloaded the new recommended driver for my service tag from the dell site, and still no ethernet controller driver is found (a yellow question mark with an exclamation mark on top in windows device manager). Tried a couple of times with the dell online chat, but was disconnected right away. Then spent another 1+ hour on the phone with dell tech support this morning. After uninstalling and reinstalling the same drivers I had previously installed, they apparently had no other suggestions and disconnected me. So I'm left with what was a pretty decent machine that is incapable of connecting to the internet.