Solved NIC won't work.

I have an ACER E5-721 laptop with a Realtek NIC that wasn't working. (In a hurry? Skip to the bottom line ... at the bottom, of course!)

I had been considering installing Linux on it for some time, and last December finally did so. (This is about the fifth time in the last 30 years that I've experimented with Linux.) After playing with it for a month I decided that Linux still hadn't developed the polish and user friendliness I wanted, so I reformatted the hard drive and reinstalled Windows 8.1. (Why not Win 10 you ask? Don't get me started on that!) The installation went smoothly and I was busy reinstalling my favorite programs on it that afternoon.

And then I hit a snag. As you well know, during the installation and configuration of many programs we need an Internet connection to register the software and check for updates, Windows itself being one of the major examples. Even though I'd earlier been accessing the 'Net with this very same machine, even though I'd been able to connect with Kubuntu, even though I was now using Windows from the very same installation disk 5 weeks earlier, I could not get it to connect now.

I have struggled for about 3 weeks now, trying every trick I could extract from the 'Net. Nothing worked. Extreme, infuriating frustratement! Then I stumbled upon a forum posting (Who knows? Maybe even on this forum! Maybe even your posting!) where a user had installed Linux as I had, then switched back to Windows, again as I had. And also couldn't connect to the 'Net with his Realtek NIC just as I had. Our hero had popped the computer's case and disconnected the battery for a while. (In my advanced age I am forgetting details. Sorry.) After letting it set disconnected for some time, they reconnected the battery, reassembled the computer, and reinstalled the drivers. Voila! Great joy! The NIC was now working.

So, as a last ditch effort before I donated it to Good Will, I popped the case on my ACER and disconnected the battery. That's when I noticed that here was a second, tiny circuit board screwed to the motherboard with the name "Qualcomm Atheros" on it! WHOA! What's that thing doing in there? Everybody including our demigods in Redmond were telling me my ACER had a Realtek NIC.

So, I went back to the ACER support pages, found the drivers and manuals page for my laptop, and discovered that ACER offers BOTH drivers. I downloaded the Qualcomm Atheros driver instead of the Realtek. It took less than 10 minutes to uninstall the Realtek drivers, reboot, and install the Qualcomm Atheros drives, reboot again (Can't be too careful here, can we?), and try to connect to the 'Net. Voila! Great joy! The NIC was now working for me too!

Bottom line: If you're one of the many people who are having trouble getting your Realtek NIC (or any other NIC for that matter) to work, especially after upgrading to a new version of Windows or after switching from another operating system like Linux, CAREFULLY take the back off your laptop and look for a network interface chip or board, and visually verify that it's really the make and model of NIC that you were led to believe.

_______________________________________________________________________

If it ain't broke, fiddle with it until it breaks, then fiddle with it until you get it fixed.
_______________________________________________________________________