Try dell.com and see if there is a network card driver for your machine.
After a problem with browser hijacker, I reformatted drive and reinstalled windows. I have a Dell 2350 running XP Home. I used the resource cd that came with the system to reinstall drivers. The resource cd does a hardware scan and I installed all the drivers for items checked. Under device manager I don`t find any listing for network adapters. The only thing showing a ? is "other devices". clicking that shows ethernet controller again with a ?.