The results of my experiment in Windows 7 and Windows 8.1 are the same. In the past, VMware Esxi was founded on this. Now, when installing Esxi, I get ‘No network adapters were detected’ error.
I have another motherboard with the same model (DX79SI) (with same CPU) and operating system Windows 10. I did not encounter such a problem on him.
Motherboard: Intel DX79SI
CPU: Intel Core i7 3820 Soket 2011 3.6GHz 10MB
Operating System: Windows 10 (I try Windows 7, Windows 8.1, Vmware Esxi)
Installed Driver: Intel® 82579LM Gigabit Ethernet PHY Last Version
I updated last BIOS Version.(650)
I still see no need for the 5-minute video. It provides nothing of substance and is a complete waste of time.
So, the board (or at a minimum the LAN ports) are bad. That is what you have proven since you have another identical board and processor. The board is 8 years old, so it is not surprising that you could be experiencing component failure.
Now, here is the important part - your board is no longer supported, regardless of operating system.