Warning
Use an administrator account for these steps, and keep a recent backup before making repair or security changes.
What you will achieve
Get wired networking back when Windows shows unidentified network or no internet on Ethernet.
1) Physical and adapter checks
- Swap Ethernet cable and try another switch/router port.
- Open Device Manager → Network adapters and disable/enable the Ethernet adapter.
- In adapter Properties → Configure → Power Management, untick power-saving options.
2) Reset IPv4 stack
Run in Admin Command Prompt:
ipconfig /release
ipconfig /renew
ipconfig /flushdns
netsh int ip reset
netsh winsock reset3) Confirm network profile
Set profile to Private in Settings → Network & Internet → Ethernet where appropriate.