Ethernet controller driver not working

I had to reinstall Windows XP after formatting the harddrive on a Dell Optiplex G280 for my sister-in-law. She does not have the installing disks, so I downloaded the drivers from Dell website. Everything works with the exception of the Eternet Controller.  In Device Manager, it shows up with an "!", so I can not connect to the internet or setup the network.  I installed the drivers on the Dell site, with no success, nothing works.  Followed suggestions on the this forum for potential fix, unsuccessful as well.  I am usually pretty good with computer, but got stump on resolving this issue.

Can some please, please point me in the right direction in getting pass this issue.  Without the Eterhnet Controller, there is no mean of connecting to the internet.

Thank you