Inspiron 580 needs Ethernet Controller Driver

I'm using Windows 7, 64 bit. 

I can connect to the Internet via WiFi but if I connect an Ethernet cable from my modem to the desktop nothing happens.  When I ran a diagnostic tune up program from AVG it said I need a driver for my Ethernet Controller.  If I check CONTROL PANEL-SYSTEM shows same thing: an orange alert where the controller driver should be.  

I couldn't find one to download for this 580 anywhere.  The guy at Dell Tech Support says they no longer have drivers for this computer since it's 9 years old.  **bleep**????

Anyone know where I might find a downloadable driver for my Ethernet Controller?  

If I can find someone who still has a 580 using 64 bit Windows 7, would it be possible to copy their driver and install it on my computer?  What would the file name be for that driver?