Ethernet controller question mark

Im trying to help a friend with her older machine with mellenium on it.
I restored it and its running fine but in device manager the ethernet
controller is showing yellow question mark and the exclamation. I have
installed the driver disk that came with it. I have tried to let it search
for drivers on the disk and the hard drive but it cant find it. I ripped it
out and restarted and it tries to reload the driver and still cant find it.
Isnt this a standard driver with windows? Anyone got anything else I and try?
I told her it might be easier just to go to worst buy and get a new ethernet
card but if the contoller in device manager isnt working would that solve the
problem?

Greg