How to Fix a Computer That Will Not Connect via Ethernet

Published 2026-10-16 · LuxuriousComputers Repair

You plug in an ethernet cable and nothing happens. The network icon shows no connection, or it shows connected but with no internet access. Wi-Fi might work fine, but the wired connection refuses to cooperate. Ethernet connection failures have a handful of common causes — the cable, the port, the network adapter settings, or the driver — and most are fixable without replacing hardware.

Check the physical connection

Ethernet is a physical connection, and the most common failures are physical:

• Cable seated fully: Push the ethernet cable into the port on both ends (computer and router or wall jack) until you hear and feel the clip click. A cable that looks plugged in but is not fully seated is the single most common cause of ethernet failure. The plastic clip on the connector can break off, allowing the cable to slip partially out of the port without being obvious
• Link lights: Look at the ethernet port on your computer. When connected properly, you should see one or two small LEDs — usually one solid (link) and one blinking (activity). If both lights are off, the physical connection is not being made. Check the router or switch port for the same lights
• Try a different cable: Ethernet cables can fail internally with no visible damage. The thin wires inside can break at the connector crimp points from repeated bending. Try a different cable that you know works (one currently in use on another device)
• Try a different port: If your router or switch has multiple ethernet ports, move the cable to a different port. A single port on the router can fail while others work. Also try a different port on your computer if it has more than one
• Direct to router: If you are connected through a wall jack or patch panel, bypass it by running a cable directly from your computer to the router. Wall jacks can have loose connections, damaged wiring, or may not be wired to an active port on the patch panel

Network adapter status

The ethernet adapter in your computer may be disabled, misconfigured, or not recognized:

Windows

1. Right-click the Start button, select Device Manager
2. Expand Network Adapters. Look for your ethernet adapter — it will be labeled with the manufacturer name (Intel, Realtek, Killer, Broadcom) followed by something like Ethernet Controller or GbE Family Controller
3. If there is a yellow triangle or red X on the adapter, the driver has a problem. Right-click it and select Update Driver, then Search automatically
4. If the adapter is not listed at all, the hardware may not be detected. Try Scan for hardware changes from the Action menu
5. If the adapter shows as disabled (down arrow icon), right-click and select Enable device

Check network connections

1. Open Settings, Network and Internet, Advanced network settings, More network adapter options (or Control Panel, Network and Sharing Center, Change adapter settings)
2. Find your ethernet adapter. If it shows Disabled, right-click and select Enable. If it shows Network cable unplugged, the physical connection is the issue — go back to the cable checks above
3. If it shows Unidentified Network or No Internet, the adapter is connected but has a configuration problem (IP address, DNS, or gateway)

IP address and DHCP

When you connect via ethernet, your computer requests an IP address from your router using DHCP. If this process fails, the computer assigns itself a 169.254.x.x address (called an APIPA address), which cannot access the internet or local network:

Check your IP address

1. Open Command Prompt and type: ipconfig
2. Find the Ethernet adapter section. If the IPv4 Address starts with 169.254, DHCP failed — your computer could not get an address from the router
3. If the IP is in your normal range (usually 192.168.x.x or 10.x.x.x) but you still have no internet, the problem is DNS or gateway configuration

Release and renew

1. Open Command Prompt as Administrator
2. Type: ipconfig /release
3. Then: ipconfig /renew
4. This forces the computer to request a new IP address from the router. If it succeeds, you will see a valid IP address. If it fails with an error about the DHCP server, the router's DHCP server may not be responding or the physical connection is still not working

Static IP conflict

If someone previously set a static IP address on this computer's ethernet adapter, it may conflict with the current network:

1. Open the ethernet adapter properties (Network Connections, right-click Ethernet, Properties)
2. Select Internet Protocol Version 4 (TCP/IPv4) and click Properties
3. If Obtain an IP address automatically is not selected, the adapter has a static IP configured. Unless you specifically need a static IP, select Obtain automatically for both IP address and DNS server

DNS issues

If the ethernet shows connected but web pages do not load while other apps (like ping to 8.8.8.8) work, the problem is DNS resolution:

• Flush DNS cache: Open Command Prompt as Administrator and run: ipconfig /flushdns
• Try public DNS: Set your DNS servers to 8.8.8.8 and 8.8.4.4 (Google) or 1.1.1.1 and 1.0.0.1 (Cloudflare) in the ethernet adapter's IPv4 properties. This bypasses your router's DNS forwarding and eliminates router DNS problems as a cause

Driver problems

Ethernet adapters require drivers. When drivers are missing, outdated, or corrupted, the adapter may not function:

• After a Windows update: Major Windows updates sometimes replace or break ethernet drivers. If ethernet stopped working after an update, go to Device Manager, right-click the ethernet adapter, select Update Driver. If that does not help, try Roll Back Driver to revert to the previous version
• After a fresh Windows install: A clean Windows installation may not include your ethernet adapter's driver. Windows includes generic drivers for common chipsets, but some adapters need manufacturer-specific drivers. Since you do not have internet to download them, you need to download the driver on another computer and transfer it via USB drive
• Download from manufacturer: Go to your computer manufacturer's support page (Dell, HP, Lenovo, etc.) or the ethernet chipset manufacturer (Intel, Realtek) on another device. Download the ethernet driver for your exact model, transfer via USB, and install

Reset network stack

If configuration problems persist, resetting the entire network stack forces Windows to rebuild all network settings:

1. Open Command Prompt as Administrator
2. Run these commands in order: netsh winsock reset
3. netsh int ip reset
4. ipconfig /flushdns
5. Restart the computer

After the restart, Windows reinitializes the network adapter with default settings. You may need to re-enter any custom network configuration, but this clears corrupted settings that prevent ethernet from connecting.

Router and network equipment

• Restart the router: Unplug the router's power for 30 seconds, then plug it back in. Wait 2 to 3 minutes for it to fully restart. A router that has been running for weeks or months can develop connection table issues that prevent new wired clients from connecting even though existing connections work
• Port security or MAC filtering: Some routers have MAC address filtering enabled, which only allows specific devices to connect. If your computer's ethernet adapter has a MAC address not in the allowed list, the connection is blocked. Check the router's settings for MAC filtering or access control lists
• DHCP pool exhausted: Routers assign IP addresses from a limited pool (typically 100 to 200 addresses). In environments with many devices, the pool can be exhausted. The router's DHCP settings page shows the pool size and active leases

Hardware failure

If nothing else works, the ethernet port or adapter hardware may have failed:

• USB ethernet adapter: As a quick test and workaround, a USB-to-Ethernet adapter (USB-A or USB-C to RJ-45) provides a completely independent ethernet connection. If the USB adapter works, the built-in ethernet port has failed. USB ethernet adapters cost between 10 and 20 dollars and work well as permanent solutions
• Surge damage: Ethernet ports are vulnerable to electrical surges that travel through the cable from the router or wall jack. A nearby lightning strike or power surge can damage the ethernet port while leaving the rest of the computer functional
• Bent pins: The RJ-45 port has small metal contacts inside. Inserting the cable at an angle or forcing a wrong connector can bend these contacts. Shine a flashlight into the port and look for obviously bent or missing contacts

Ethernet repair in Columbus or Delaware

If your computer's ethernet connection is not working and the troubleshooting above did not resolve it, LuxuriousComputers can diagnose the ethernet adapter hardware, check for driver or configuration issues, and replace the ethernet port or provide an alternative wired connection solution.