I had the same problem here with a Dimension 3000. Reformated the HD and reinstalled both the Windows Home O/S and utilities/drivers from the original Dell disks. Everything installed except the ethernet controller. Hunted all over the Dell site - no luck. Hunted all over the Intel site. No luck. Called Dell support - they had the audacity to want over $250 to talk to me - presumably to make excuses as to why the driver was not on the original disk...
What fixed it was running Windows Update. I'm not sure what specific update did it as I ran a whole pack of updates - but I think it was probably the (optional) hardware update for the network interface.
Anyway it fixed it ...
Re: Dell Dimension 3000 Ethernet & Multimedia Drivers 
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