Check both ends of the cable and the port lights, try another cable and router port, make sure the adapter is enabled in ncpa.cpl, update the Ethernet driver (Realtek/Intel), then run Network reset. If a dock or USB adapter is involved, test the PC's own port.

What's going on

Ethernet failures split into two groups. If there are no link lights or Windows says the cable is unplugged, it’s physical: the cable, port, dock or adapter. If the link is up but there’s no internet or an “unidentified network”, it’s IP/DNS or driver configuration.

Laptops using USB-C docks or USB Ethernet adapters add a driver layer that often needs its own update.

Symptoms

  • “Network cable unplugged” or a red X on the network icon.
  • “Unidentified network” / “No internet” on Ethernet.
  • Ethernet adapter missing from Device Manager.

Why it happens

  • Faulty cable, port, dock or USB adapter.
  • Disabled adapter or outdated/corrupted driver.
  • IP/DNS misconfiguration.
  • Router port or switch issue.

Try these fixes

  1. Check the physical linkLook for lights on the port. Try a different cable and router port. Cat5e or better is fine for gigabit.
  2. Enable the adapterRun ncpa.cpl. If Ethernet is greyed out, right-click → Enable.
  3. Update or reinstall the driverInstall the latest Realtek/Intel/Killer Ethernet driver from the maker, or uninstall the device in Device Manager and restart.
  4. Reset IP and DNSRun the commands below, set IPv4 to obtain addresses automatically, and restart.
  5. Network resetSettings → Network & internet → Advanced network settings → Network reset.
  6. Bypass the dockTest with the PC's built-in port or another adapter; update dock firmware.

Command

netsh winsock reset
netsh int ip reset
ipconfig /release
ipconfig /renew
ipconfig /flushdns

Run in an elevated Command Prompt, then restart Windows.

How to tell it worked: Ethernet shows 'Connected' with internet access and the expected link speed (Settings → Ethernet).

Avoiding it in future

Use good-quality cables and keep Ethernet and dock drivers updated.