The Problem

You plugged in Cat5e/Cat6 but Windows shows Unidentified network, No internet, or the Ethernet port acts dead while Wi-Fi is fine. Wired should be the most reliable link—when it fails, the cause is usually cable/link, a disabled adapter, wrong driver, or DHCP—not the ISP.

Wi-Fi issues instead? See can't connect to this network, no internet secured, or slow Wi-Fi speeds.

Symptoms

Ethernet icon missing or shows disconnected with cable plugged in.
Network connections (ncpa.cpl) shows adapter disabled or "Network cable unplugged."
Link lights on the PC port or router port are off (no amber/green).

The Fix: Step-by-Step

Step 1: Physical Layer First

Firm click until the RJ45 latch clicks—try another known-good cable.
Plug into a different LAN port on the router or switch.
Check link LEDs on the PC jack and router—no lights often means bad cable, dead port, or loose crimp.
Avoid USB Ethernet adapters on unpowered hubs for the first test—go direct to the motherboard port.

Step 2: Enable the Adapter

Win + R → ncpa.cpl → Enter.
If Ethernet is gray, right-click → Enable.
Settings → Network & internet → Ethernet—confirm it sees a connection.

Step 3: Run the Network Troubleshooter

Right-click network icon → Diagnose network problems → apply fixes offered. Note the error code if it fails.

Step 4: Reset TCP/IP Stack

Admin Terminal:

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

Reboot after.

Step 5: Set IPv4 to Automatic (DHCP)

ncpa.cpl → Ethernet → Properties.
Internet Protocol Version 4 (TCP/IPv4) → Properties.
Obtain an IP address automatically and Obtain DNS server automatically unless your IT gave static IPs.
Optional DNS test: Preferred 1.1.1.1, Alternate 1.0.0.1—see DNS not responding if names do not resolve.

Step 6: Reinstall the Ethernet Driver

Device Manager → Network adapters → your Realtek/Intel/Killer Ethernet device.
Right-click → Uninstall device → check Attempt to remove the driver if shown → reboot.
Install the latest driver from the motherboard or laptop vendor support page—match your exact model.
Avoid generic "driver updater" bundles.

Step 7: Disable Power Saving on the Adapter

Device Manager → Ethernet adapter → Properties → Power Management.
Uncheck Allow the computer to turn off this device to save power.
Advanced tab → disable Energy-Efficient Ethernet / Green Ethernet if link drops after sleep.

Step 8: Disable Conflicting VPN or Virtual Adapters

Old VPN, VirtualBox, or Hyper-V virtual switches can hijack routes.

ncpa.cpl → disable unused TAP / Virtual adapters you do not need.
Settings → Network & internet → VPN → disconnect test VPNs.

Step 9: Network Reset (Last Resort)

Settings → Network & internet → Advanced network settings → Network reset. Reboot, re-plug cable, re-enter Wi-Fi passwords if the PC is dual-connected.

Still Dead?

Router LAN port failed—try another port or factory-reset router (last resort).
Onboard NIC failed—USB Ethernet dongle is a cheap workaround until board repair.
PC works on another network but not home? ISP modem bridge mode or VLAN settings—call ISP with link-light status.

How to Fix Ethernet Not Working in Windows 11