After a clean Windows install, not much works on some PC.
In short, after the OS I install motherboard and LAN drivers. These are specific to your PC so I can't do much more than share the general idea of what needs to be done next.
If your model has factory recovery media, this is far easier than driver hunts (unless it's a Dell.)
Recently i installed (again) windows 7 after some issues regarding windows 10. Long story short, i reinstalled windows 7 and to my surprise, it didn't detected my trusty LAN cable. It was connected during installation and it was working fine back in the windows 10 days (like the day before all of this mumbling disaster happened).
I've tried recreating the connection, but it didn't work. Tried on safe mode with network features,didn't worked either.
Proof: (Note: it was still on safe mode with network features when this was recorded)
Any help is welcome. Thanks for your attention and assistance.