Testing onboard LAN for defect????

Xperts:
I'm going to make a call on an elderly guy for whom I built a little system a year ago. The sequence of this problem is that we had some foul weather and in the midst the Time-Warner roadrunner service went out. When it came back, his speed was very low and I suspected the problem was on Time-Warner's end so he called, they came out to the home. The did some work [not sure what] which resulted in the network now being TOTALLY off/gone/history/defunct, and they blamed the onboard LAN controller saying it had "died". Claimed their modem & signal were all right on spec.

So - if they are right it will be a first. I personally have never seen an onboard LAN controller die other than a DOA.
If the driver is corrupt, i figure Win98 [his only license] is not going to accurately loopback to actually test function of the controller. How do I first verify the controller is OK, then go about re-installing a good driver [I know how to do the latter... its the former I'm unsteady about]

thx
z

 

Im not aware of any really good way to test the adapter other then pinging the loopback address which really isn't much of a good test. Best bet would be to just reinstall the driver and if its still not working the replacing the nic as they are a pretty cheap component.