Ethernet Not Working: Troubleshooting Guide

Quick Answer

If your Ethernet connection is not working, the most common causes are a faulty cable, an incorrect network adapter driver, or a misconfigured IP address. Start with the physical layer - swap the cable and check the port - before diving into Windows settings.

A dead Ethernet connection is one of the most frustrating tech problems because Wi-Fi is an obvious fallback, but for gaming or work-from-home setups in South Africa, a wired connection is often essential for avoiding the latency spikes and packet loss that wireless brings. Whether you are on a desktop build or a laptop docked at a home office, this guide walks through the full troubleshooting sequence.

Check the Physical Connection First

Before touching software, go physical. Unplug the Ethernet cable from both your PC and your router or wall port, then plug it back in firmly - you should hear a click. If the link lights on your router port or NIC are not lighting up at all, the cable itself is likely the culprit. Try a different cable if you have one. Also inspect the RJ45 connector on your cable for bent pins. If you are connected through a wall plate, test by running a cable directly from the router to rule out a faulty wall port. Many South African homes and offices have aging Cat5e runs that can develop faults over time.

Fix Driver and Adapter Issues in Windows

If the physical check passes but the connection still does not work, open Device Manager (right-click Start, select Device Manager) and expand Network Adapters. Look for any yellow warning icons next to your Ethernet adapter. Right-click the adapter and choose Update driver, then Search automatically for drivers. If Windows cannot find one, visit your motherboard or laptop manufacturer's support page and download the LAN driver manually. A common fix is to right-click the adapter, select Disable device, wait 10 seconds, then re-enable it. This forces Windows to reinitialise the connection.

Reset Network Settings and IP Configuration

A corrupted TCP/IP stack or a stuck DHCP lease can also block a working Ethernet connection. Open Command Prompt as Administrator and run these commands in order:

netsh winsock reset

netsh int ip reset

ipconfig /release

ipconfig /flushdns

ipconfig /renew

Restart your PC after running all five. If your router is assigning an address in the 169.254.x.x range, that is a self-assigned IP, which means DHCP failed - restarting your router or modem will usually resolve this. South African ISPs like Fibre providers often require the router to fully reboot before reassigning leases correctly.

Frequently Asked Questions

Q: My Ethernet shows "connected" but there is no internet - what is wrong? A: This usually means your connection to the router is fine but the router has lost its WAN link. Restart your router and check with your ISP whether there is an outage in your area.

Q: Can a bad Ethernet port on my motherboard be repaired? A: A faulty onboard LAN port can be bypassed cheaply by adding a PCIe or USB Ethernet adapter. This is often faster and more cost-effective than motherboard repair in SA.

Q: Why does my Ethernet work on one PC but not another? A: The issue is almost certainly a missing or corrupted driver on the affected machine. Download the correct LAN driver from the manufacturer's site and install it manually.