This is a well documented problem with some suggested workarounds, but the circumstances around this problem are unusual so I thought I'd raise the issue again.
I have an Asus P5B-E motherboard with an integrated Atheros L1 gigabit Ethernet adapter. I'm running Windows 7 Professional 64-bit.
I've had the same basic hardware and OS running virtually 24x7 for the past couple of years, and have never had any network problems (other than issues with my Comcast ISP) until now.
I recently started streaming video from my PC to my iPad (via Air Playit), and immediately started seeing my PC's network connections disappear. Basically I would lose all inbound and outbound connections. Running Network Troubleshooter always repaired the problem by resetting the Atheros adapter, and all would be well again for a few minutes, or a few hours or a few days, until the same problem would reappear. (Trying to stream a video over Air Playit seemed the easiest way to trigger the problem.)
At first I thought this might be an issue with th Air Playit server, so I simply uninstalled it. However the problem persisted. I then checked my event logs and sure enough, I found multiple error entries for source AtcL001. Here's a sample error's detail:
The description for Event ID 194 from source AtcL001 cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.
If the event originated on another computer, the display information had to be saved with the event.
The following information was included with the event:
The specified resource type cannot be found in the image file
The same error events could be found only as far back as 10/29 (15 days ago), before I installed Air Playit. What was significant about 10/29 was that's the day when my home switched over to generator power during hurricane Sandy (I live in NH; we were without power for approx. 25 hours). So I'm wondering if this could potentially be a hardware problem with the Atheros adapter embedded on my motherboard.
The event log shows the same AtcL001 errors occurring off and on on 11/2, 11/13 (yesterday) and today. That's it. No other instance of this error appears for the two years prior.
I checked my Windows Update log to see if any updates were installed at the time of the first error on 10/29. Nothing that day, and nothing in the week or so before then that seemed related.
I just implemented one of the suggested workarounds to this problem, by turning off the Atheros adapter's 'Task Offload' property. So far I've not seen another network disconnect (I did try streaming some music from my PC to another PC via iTunes), but time will tell.
Has anyone else seen or dealt with this problem? Any thoughts on whether you think this might be an actual hardware problem?
Try a different ethernet cable, sometimes the plugs and the cable itself fail over time, one of my cables went faulty after 3 years of use, I was able to fix it by re-crimping the connectors, but it might be better to just replace the cable.
anaonymous1: Thanks, I'm planning to do just that. I see from many other online comments that NIC's seem to be a favorite target of lightning strikes. Odd though, given that my PC is plugged into a UPS that should provide adequate isolation from that sort of thing.
hairystuff: I hadn't considered a bad network cable, but it's easy enough to switch it out and then retest (with Task Offload turned back on) to see if a different cable has any effect.