Update
* Attempted to go under Device Manger / Click on the Network Controller (has a yellow /!\ icon), and specified the location of the uncompressed drivers installation, clicking "and subfolders". Windows is searching for drivers, but failing to find/install one.
* Read the readme.txt in the uncompressed drivers file; and saw that Microsoft Package Installation service should be running. It was set to manual. Started it and attempted drivers installation from intel website downloaded .exe; same error as before.
* The readme clearly states that the 8.1 driver is supposed to work with Win2012R2/64...
So... No progress...