Before you start
- A spare Ethernet cable (for testing)
Method 1 Check the hardware
-
Step 1: Reseat the cable
Unplug and replug both ends until they click.
-
Step 2: Swap cable and port
Try another Ethernet cable and a different port on the router. Cables bend and break inside.
-
Step 3: Check the lights
The PC’s Ethernet port should show a steady and/or blinking light. No lights = cable, port or adapter problem.
-
Step 4: Test another device
Plug a laptop into the same cable. If it works, the problem is your PC.
Method 2 Check Windows settings
-
Step 1: Enable the adapter
Go to Settings > Network & internet > Advanced network settings and make sure Ethernet is enabled.
-
Step 2: Check IP settings
In Settings > Network & internet > Ethernet, IP assignment should be Automatic (DHCP).
-
Step 3: Renew the IP
In Terminal (Admin), run ipconfig /release and ipconfig /renew.
Method 3 Fix the driver
-
Step 1: Open Device Manager
Right-click Start > Device Manager > Network adapters. Look for Realtek, Intel or Killer Ethernet.
-
Step 2: Update or reinstall
Download the latest LAN driver from your PC or motherboard maker. Or right-click > Uninstall device and restart.
-
Step 3: Disable power saving
Right-click the adapter > Properties > Power Management and untick Allow the computer to turn off this device. In the Advanced tab, turn off Energy Efficient Ethernet if available.
Troubleshooting
“Unidentified network” on Ethernet
The PC isn’t getting an IP address. Restart the router, renew the IP, and check the router’s DHCP is on.
Ethernet connects at only 100 Mbps
The cable may be old (Cat5) or damaged. Use a Cat5e or Cat6 cable.
Frequently asked questions
Do I need a special cable?
Any Cat5e, Cat6 or newer cable supports gigabit speeds.
My laptop has no Ethernet port
Use a USB-C or USB-A Ethernet adapter; most work without drivers.
Summary
Swap the cable and port first, check the adapter is enabled with automatic IP, update the Ethernet driver and renew the IP. A Network reset fixes the rest.
