How to Fix Ethernet Not Working on Your Computer

Published 2026-10-16 · LuxuriousComputers Repair

A wired ethernet connection that stopped working is frustrating because ethernet is supposed to be the most reliable way to connect. Unlike Wi-Fi, there is no signal strength to worry about, no interference from other devices, and no password to re-enter. When ethernet stops working, the cause is almost always something specific and fixable — a cable problem, a driver issue, a network configuration error, or a hardware failure in the port itself.

Check the physical connection first

Before touching any settings, verify the basics. Physical problems cause the majority of ethernet failures.

The cable

  • Is the cable fully seated? Push the RJ45 connector firmly into both the computer's ethernet port and the router or wall jack until you hear and feel a click. Ethernet connectors have a small plastic latch that holds them in place — if the latch is broken, the cable can slowly work itself loose and make intermittent contact
  • Check the link lights. Most ethernet ports have one or two small LEDs next to or inside the port. When a cable is properly connected, at least one light should be on (solid or blinking). No lights at all means the port is not detecting a cable — try a different cable
  • Try a different cable. Ethernet cables get damaged by being bent at sharp angles, pinched by furniture, chewed by pets, or simply wearing out at the connector. Swap in a known-good cable. If you do not have a spare, cables are inexpensive — any Cat 5e or Cat 6 cable from a store will work
  • Try a different port on the router. If the cable and computer port both look fine, the router port may be dead. Plug into a different numbered port on the router (not the WAN port, which is usually a different color or labeled Internet or WAN)

The port

Look inside the computer's ethernet port with a flashlight. Check for bent pins — the port has a row of small gold contacts that must make contact with the cable connector's pins. If any are bent, pushed in, or missing, the port is physically damaged. On a desktop, a damaged port on the motherboard can sometimes be worked around by installing a PCIe ethernet card ($15 to $25). On a laptop, a USB-to-ethernet adapter ($10 to $20) is the simplest workaround for a damaged built-in port.

Check the network adapter status

Open the Network Connections window: press Windows + R, type ncpa.cpl, press Enter. Look for your ethernet adapter — it is usually labeled Ethernet or Local Area Connection.

  • If the adapter shows a red X: The cable is not detected. This is a physical problem (cable, port, or router port) or the adapter is disabled
  • If the adapter says Disabled: Right-click it and select Enable. It may have been disabled by software, a power management setting, or accidentally
  • If the adapter says Unidentified Network or No Internet Access: The cable is connected but the network configuration is wrong — skip to the IP configuration section below
  • If there is no ethernet adapter listed at all: The driver is missing or the hardware is not detected — skip to the driver section below

Reset the network configuration

Corrupted network settings are a common cause of ethernet working at the physical level (lights on, adapter shows connected) but no internet access. Resetting clears these settings.

Open Command Prompt as administrator and run these commands one at a time:

  1. ipconfig /release — releases the current IP address
  2. ipconfig /flushdns — clears the DNS cache
  3. netsh int ip reset — resets TCP/IP stack to defaults
  4. netsh winsock reset — resets the Winsock catalog (socket layer)
  5. ipconfig /renew — requests a new IP address from the router

Restart the computer after running all five commands. When it comes back up, check if ethernet is working.

Check your IP configuration

If the network reset did not help, check what IP address your computer has. Open Command Prompt and run ipconfig. Look at the Ethernet adapter section:

  • IPv4 Address starting with 169.254: This is an APIPA address, which means your computer could not get an IP address from the router's DHCP server. The router is not responding to the computer's request. Check that the router is on and functioning, try a different port on the router, or restart the router
  • IPv4 Address starting with 192.168 or 10.x: You have a valid local IP. If you still cannot reach the internet, the problem is DNS or the router's internet connection, not your ethernet. Try ping 8.8.8.8 — if that works but websites do not load, it is a DNS issue (change DNS to 8.8.8.8 and 8.8.4.4 in adapter settings)
  • No IPv4 address at all: The adapter is not configured. Check if it is set to DHCP: right-click the ethernet adapter in ncpa.cpl, Properties, select Internet Protocol Version 4, Properties. Make sure Obtain an IP address automatically and Obtain DNS server address automatically are both selected

Static IP conflicts

If someone previously set a static IP on your ethernet adapter (for a printer, a server, or a specific network), that static IP may not work on your current network. The signs: the adapter shows connected but you cannot reach anything, and ipconfig shows an IP that does not match your router's subnet. Switch to DHCP (automatic) unless you specifically need a static IP for a reason you know about.

Update or reinstall the ethernet driver

If the ethernet adapter does not appear in Network Connections at all, or if it appears with a yellow warning icon in Device Manager, the driver is the problem.

  1. Open Device Manager (right-click Start, Device Manager)
  2. Expand Network adapters. Look for your ethernet adapter — it may be listed by chipset name (Realtek, Intel, Killer, Broadcom) rather than as "Ethernet"
  3. If it has a yellow exclamation mark, right-click it and select Update driver, then Search automatically for drivers. Windows will attempt to find and install the correct driver
  4. If no ethernet adapter is listed, look under Other devices for an Unknown device with a yellow mark — that may be the unrecognized ethernet chip. You need to download the driver from the motherboard manufacturer's website (for desktops) or the laptop manufacturer's website on another computer, copy it via USB, and install it manually

Reinstall the driver

If the adapter is listed but not working correctly even with the latest driver, uninstalling and reinstalling often fixes corruption:

  1. In Device Manager, right-click the ethernet adapter
  2. Select Uninstall device. Check the box for Attempt to remove the driver for this device if available
  3. Restart the computer. Windows will automatically detect the hardware and reinstall a default driver on boot
  4. If Windows does not find a driver automatically, install the one you downloaded from the manufacturer

Check power management settings

Windows can turn off the ethernet adapter to save power, which causes the connection to drop intermittently or after sleep or hibernation.

  1. In Device Manager, right-click the ethernet adapter and select Properties
  2. Click the Power Management tab
  3. Uncheck Allow the computer to turn off this device to save power
  4. Click OK

Also check the Advanced tab for settings like Energy Efficient Ethernet, Green Ethernet, or Power Saving Mode. Disable these if ethernet keeps dropping — they reduce the link speed or shut down the port when they detect low traffic, which can be too aggressive on some hardware.

Check for VPN or firewall interference

VPN software installs virtual network adapters that can interfere with your physical ethernet connection. If ethernet stopped working after installing a VPN:

  • Disconnect the VPN and test
  • Check Network Connections (ncpa.cpl) for virtual adapters created by the VPN. If the VPN's TAP adapter has a higher priority than your ethernet adapter, traffic may be routing through the VPN tunnel even when it is not connected
  • Uninstall and reinstall the VPN if it corrupted the network stack

Similarly, overly aggressive firewall software (especially third-party security suites like Norton, McAfee, or Kaspersky) can block ethernet traffic. Temporarily disable the firewall to test — if ethernet works with it off, the firewall's network rules need adjustment.

Test with another device

If nothing above works, determine whether the problem is the computer or the network by testing with another device. Plug the same ethernet cable into the same router port but connect it to a different computer, laptop, or even a gaming console. If the other device gets internet, the problem is your computer's hardware or software. If the other device also has no internet, the problem is the cable, router, or ISP.

Ethernet repair help in Marion

If your ethernet connection is not working and the troubleshooting above has not resolved it, LuxuriousComputers Repair in Marion can diagnose whether the issue is a damaged port, a driver problem, or a network configuration issue and get your wired connection working again.

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