My recommendations is to do a clear installation of the Operating System. The first driver you must install is the chipset driver then the Intel® Management Engine.
After that, try installing this driver for LAN:
Let me know how it goes!
What you're suggesting is a full day of work. And the only difference that I see between what I did originally and your suggestion is the order of driver installation. How confident are you that scraping and re-installing will produce anything different than what I now have?
Nutshellization - problem solved.
After spending over 16 hours scraping and reinstalling, I was back where I started.
I spent some time in Device Manager and came to the conclusion that the problem was with the WiFi, not the LAN driver. I had dismissed this idea before, but it kept nagging at me. I had previously installed all the WiFi and Bluetooth drivers recommended in the "WYK-WYB-Win7-64bit-Driver-Bundle-Mar2015." This was the bundle I downloaded on 4-15-2015.
Today I took a chance and went looking for a WiFi driver that mapped to my 7260-AC. Found this - Intel® PROSet/Wireless Software and Drivers for Windows 7*. Note the date of the files - 4-20-2015. I installed the version for my Win7 64-bit OS and just like magic, the errant Network Controller problem vanished.
The Manageability Engine Firmware Recovery Agent still doesn't work, but I'm resigned to it being non-functional.