Intel mac adresses are invalid in...

I just noticed you aren't very far from where I live, small world indeed.

So I think you did a UEFI/BIOS clear by removing the battery on the board? Is that right?

I'm not saying that is a mistake, it isn't, just wondering... any chance the battery got put back upside down? All you should see is silver looking down at the battery.

I think you said in another post that your Internet is working for you now, is that correct? If it is, and you just see that message when you start the PC, it's not a big problem.

I hope you tried to connect to the Internet even after you saw this message.

What kind of Internet service do you have in Braidwood? Comcast down there, or something else like AT&T?

You're using Windows 10?

Did you install the Intel network driver from the board's disk or the download page for your board? Assuming Windows 10, although it is the same version for any recent version, the Lan driver ver:20.2 here:

http://www.asrock.com/mb/Intel/Z170%20Extreme4/?cat=Download&os=Win1064

I'm not saying you must install the Intel network driver to get rid of that message, but it might help sort things out for you.

What I want you to try is to clear the UEFI/BIOS again. But this time do not take out the battery.

Your board has a tiny switch on the IO panel, where the connectors for the USB 3.0 ports and onboard video outputs are. There is a small opening in the metal cover and you'll see a small dark circle through the opening. That is the Clear CMOS switch, used to clear the UEFI/BIOS in a manner similar to removing the battery, but not as extensive as removing the battery.

With the PC shutdown, PSU turned off and unplugged from power, use a Q-tip or similar small object to put through that hole and press the switch, like pressing a button that will pop up when you stop pushing on it. Push down carefully but enough to feel it move and then stop moving. Count to five or so, and release the button. Do that again for a count of five or so, and release. You're done clearing the UEFI/BIOS!

Power up and start the PC. Starting the PC after clearing the UEFI will take longer, it may start and then shutoff, and then will start again on its own. That's normal, just let it be if it shuts off.

You'll be prompted on the screen to enter the UEFI/BIOS screens if you need to set any options you need. If you don't need to, the PC will continue booting after a timer on the screen runs out.

NOTE that the fans connected to the board may run at full speed since the UEFI clear will set their speed profile back to the default setting. That is also normal.

It might take a restart or two before that message disappears.

Of course if you can't connect to the Internet, let us know.