A broken Ethernet connection in Windows 10 is usually fixable with a few checks — the most common causes are physical cable/port faults, adapter settings or drivers, and IP/DNS misconfiguration. This article explains why Ethernet doesn’t work in Windows 10 and gives 14 practical fixes so you can diagnose and repair the problem step by step.
You’ll learn how to verify hardware, test and reset network settings, update or roll back drivers, fix Windows services and firewalls, and when to replace hardware or contact support.
Key Takeaway
Most Ethernet problems in Windows 10 are either physical (cable/port) or software (driver/IP/Windows settings); start with a cable and link-light check, then update/reset drivers and run the built-in network reset (Settings > Network & Internet > Network reset) before trying hardware replacement.
Quick Fix Guide
| Reason for the Problem | Quick Solution |
|---|---|
| 1. Damaged or bad Ethernet cable | Replace the cable with a known-good CAT5e/CAT6 cable. |
| 2. Cable not fully connected or wrong port | Reseat the cable and try another port on the PC/router/switch. |
| 3. Router/switch/modem issue | Reboot router/modem/switch and test another downstream port. |
| 4. Network adapter disabled | Enable the adapter in Settings > Network & Internet > Change adapter options. |
| 5. Driver missing, incorrect, or corrupt | Update, roll back, or reinstall NIC driver in Device Manager (devmgmt.msc). |
| 6. Power management turning off adapter | Disable “Allow the computer to turn off this device to save power” in adapter properties. |
| 7. Incorrect IP settings (static conflict) | Switch to Obtain IP address automatically (DHCP) or set correct static IP/gateway. |
| 8. DNS or proxy misconfiguration | Remove proxy and use automatic DNS (or set public DNS like 1.1.1.1 / 8.8.8.8). |
| 9. Windows Firewall blocking network | Temporarily disable firewall to test, then create allowed rules. |
| 10. VPN/antivirus or security software conflict | Temporarily disable VPN/antivirus and test connectivity. |
| 11. Corrupted TCP/IP or Winsock stack | Run netsh winsock reset and netsh int ip reset, then reboot. |
| 12. Recent Windows update regression | Roll back the update or use System Restore to undo changes. |
| 13. Failing network adapter hardware | Test with USB Ethernet adapter or another PC to confirm hardware failure. |
| 14. Duplex/speed mismatch or advanced NIC settings | Set adapter speed/duplex to Auto Negotiation or match router settings. |
Detailed Fixes for “Ethernet doesn’t work in Windows 10”
1. Damaged or bad Ethernet cable
Why it causes the problem:
A damaged cable may break the physical connection or cause intermittent packet loss, preventing link establishment.
Step-by-step solution:
- Inspect the cable for visible cuts, kinks, or bent pins on the RJ45 connectors.
- Swap the cable with a known-good cable (preferably CAT5e or CAT6).
- Check the network jack link lights on the PC NIC and the router/switch when plugged in; lights usually indicate link/activity.
- If cable runs through wall jacks, test at the patch panel or use a short cable to the router to isolate wall wiring.
Tip: If you frequently move the cable, replace with a flexible stranded cable; for long runs, use solid-core cables.
2. Cable not fully connected or wrong port
Why it causes the problem:
A partially seated connector or wrong port (e.g., plugging into a phone jack) won’t create a proper link.
Step-by-step solution:
- Unplug the Ethernet cable and plug it back in until you hear a click.
- Try a different port on the router, switch, or PC.
- On laptops with multiple ports or docking stations, connect directly to the laptop to rule out dock faults.
- Verify the port label (LAN/Internet/WAN) to use the correct one on modems/routers.
Note: Some routers have dedicated WAN ports that won’t connect to a local switch.
3. Router/switch/modem issue
Why it causes the problem:
The upstream device might be faulty, misconfigured, or overloaded.
Step-by-step solution:
- Reboot the router/modem: unplug power, wait 30 seconds, plug back in.
- Test another device on the same Ethernet port to see if it gets a link.
- If multiple ports fail, factory-reset the router (note: this erases settings) or check the router’s status page.
- Check provider status or try plugging the PC directly into the modem if available.
Tip: If the router uses VLANs or port security, ensure the port is enabled for your device.
4. Network adapter disabled in Windows
Why it causes the problem:
If the adapter is disabled, Windows won’t use it, so no network traffic flows.
Step-by-step solution:
- Open Settings > Network & Internet > Status and click Change adapter options (or run ncpa.cpl).
- If the Ethernet adapter shows as Disabled, right-click and choose Enable.
- If it’s hidden, open Device Manager (devmgmt.msc) > Network adapters, and check if the device is disabled (down arrow) — right-click > Enable device.
Tip: Shortcuts: Win + X > Network Connections in newer builds.
5. Driver missing, incorrect, or corrupt
Why it causes the problem:
Faulty or outdated drivers prevent the NIC from communicating with Windows and the network.
Step-by-step solution:
- Open Device Manager (devmgmt.msc) > expand Network adapters.
- If the NIC has a yellow triangle, right-click > Update driver > Search automatically for drivers.
- If updating fails, right-click > Uninstall device (check Delete the driver software for this device if present), then reboot; Windows will reinstall drivers.
- For best results, download the latest driver from the NIC or PC manufacturer’s website and install it manually.
- If a recent driver update caused the issue, in Device Manager right-click > Properties > Driver tab > Roll Back Driver.
Tip: Keep a USB copy of drivers before uninstalling so you can install if Windows can’t auto-download.
6. Power management turning off the adapter
Why it causes the problem:
Windows power-saving settings may turn off the NIC to save battery, cutting the connection.
Step-by-step solution:
- Open Device Manager > Network adapters > right-click NIC > Properties.
- Go to Power Management tab and uncheck Allow the computer to turn off this device to save power.
- On laptops, open Control Panel > Power Options > Change plan settings > Change advanced power settings > expand PCI Express and Link State Power Management set to Off.
- Reboot and test connectivity.
Note: This is often the cause on laptops after sleep/resume.
7. Incorrect IP settings (static conflict)
Why it causes the problem:
A wrong static IP, netmask, gateway, or duplicate IP on the network prevents successful IP communication.
Step-by-step solution:
- Open Control Panel > Network and Sharing Center > Change adapter settings.
- Right-click Ethernet > Properties > select Internet Protocol Version 4 (TCP/IPv4) > Properties.
- Choose Obtain an IP address automatically and Obtain DNS server address automatically, then OK.
- If you need a static IP, confirm correct IP address, Subnet mask, Default gateway, and DNS — ask your network admin or check router’s DHCP range to avoid conflicts.
- Run Command Prompt (admin) and execute ipconfig /release then ipconfig /renew.
Tip: Use ipconfig /all to inspect current IP configuration.
8. DNS or proxy misconfiguration
Why it causes the problem:
If DNS is wrong you may have network connectivity but cannot resolve domain names; proxies can redirect or block traffic.
Step-by-step solution:
- Check proxy: Settings > Network & Internet > Proxy and ensure Use a proxy server is off (unless required).
- Under adapter properties > Internet Protocol Version 4 (TCP/IPv4) > Properties, set DNS to automatic or use public DNS like 8.8.8.8 and 1.1.1.1.
- Flush DNS cache: open Command Prompt (admin) and run ipconfig /flushdns.
- Test name resolution with nslookup www.example.com and ping an IP like 8.8.8.8 to differentiate DNS vs connectivity issues.
Tip: If pinging IPs works but DNS names don’t, it’s a DNS problem.
9. Windows Firewall blocking network
Why it causes the problem:
Incorrect firewall rules or profiles (Public vs Private) can block network traffic.
Step-by-step solution:
- Temporarily disable Windows Firewall: Control Panel > Windows Defender Firewall > Turn Windows Defender Firewall on or off > select Turn off for testing.
- If connectivity returns, re-enable firewall and go to Advanced settings to check inbound/outbound rules for your adapter or app.
- Ensure network is marked Private if you trust home/work networks: Settings > Network & Internet > Ethernet > click network name > set Private.
- If using third-party firewall, open its console and allow traffic or disable it temporarily.
Warning: Only disable firewall for brief testing.
10. VPN, antivirus, or security software conflicts
Why it causes the problem:
These programs may alter network routing, block connection types, or install virtual adapters that interfere with Ethernet.
Step-by-step solution:
- Disable VPN client and test connectivity.
- Temporarily disable antivirus/Internet security suites (look for shield icon in system tray).
- If the issue clears, re-enable security software and check its network settings or reinstall the software.
- Remove unused virtual adapters in Device Manager or Network Connections.
Note: Some VPN clients require a reboot after uninstall.
11. Corrupted TCP/IP or Winsock stack
Why it causes the problem:
Corruption in the TCP/IP stack or Winsock can break networking even when hardware and drivers are fine.
Step-by-step solution:
- Open Command Prompt (admin).
- Run: netsh winsock reset and press Enter.
- Run: netsh int ip reset and press Enter.
- Reboot the PC.
- If still failing, run sfc /scannow and DISM /Online /Cleanup-Image /RestoreHealth to check system file integrity.
Tip: These commands often fix issues after malware removal or misbehaving network software.
12. Recent Windows update regression
Why it causes the problem:
A Windows update can introduce driver or settings incompatibilities causing Ethernet to fail.
Step-by-step solution:
- Check Settings > Update & Security > Windows Update > View update history for recent updates.
- If you suspect an update, go to Settings > Update & Security > Recovery and use Go back to the previous version of Windows 10 (if available).
- Alternatively, uninstall the specific update: Settings > Update & Security > Windows Update > View update history > Uninstall updates.
- After uninstall, hide the update using the Microsoft Show/Hide tool until a fixed update is released.
Note: Create a restore point regularly — use System Restore to revert to a known-good state.
13. Failing network adapter hardware
Why it causes the problem:
Physical failure in the NIC means it cannot transmit or receive packets reliably.
Step-by-step solution:
- Test the NIC on another computer or test your computer with another NIC (USB-to-Ethernet adapter) to confirm.
- In Device Manager, check for frequent disconnects or hardware errors in the Event Viewer logs (Windows Logs > System).
- If confirmed, replace the NIC: use a USB Ethernet adapter or replace an internal PCIe NIC.
- Install drivers for the new adapter and test.
Tip: USB NICs are a quick, inexpensive diagnostic and temporary fix.
14. Speed/duplex mismatch or advanced NIC settings
Why it causes the problem:
If the PC and switch/router negotiate different speeds or duplex, connections may be slow, drop packets, or not establish.
Step-by-step solution:
- Open Device Manager > Network adapters > right-click NIC > Properties > Advanced tab.
- Locate Speed & Duplex, set it to Auto Negotiation first. If issues continue, try manual settings like 100 Mbps Full Duplex to match router/switch.
- In the router/switch management interface, ensure the port is set to auto or matches your NIC setting.
- Test for improvement; use ping -n 50 8.8.8.8 to check packet loss.
Note: Force-matching may be necessary on older switches.
Maintenance and When to Contact Support
- Regular maintenance: Keep Windows updated, drivers current, and maintain spare cables and a USB Ethernet adapter for quick swaps.
- Backup network configuration: Note any static IPs, DNS, or proxy settings before resetting.
- Contact support when: You’ve tested another device on the same port/cable, replaced the cable and adapter, and still have no link — your ISP or hardware vendor can run line tests or RMA defective devices.
- Log useful info: Before calling support, collect ipconfig /all, device manager screenshots, and error messages to speed troubleshooting.
FAQ
Q: How do I tell if the problem is local (PC) or the ISP/router?
A: Test another device on the same Ethernet port/cable; if it works, the issue is your PC. If other devices fail, reboot the router/modem and contact the ISP.
Q: Will Network reset erase important settings?
A: Network reset (Settings > Network & Internet > Status > Network reset) removes and reinstalls network adapters and resets settings; you’ll need to reconfigure VPNs, virtual adapters, and some custom settings, so note them first.
Q: Can a Windows Defender or security update break Ethernet?
A: Yes — rare updates can conflict with drivers or networking components; check update history and roll back if needed.
Q: How can I permanently avoid Ethernet disconnections on a laptop?
A: Disable power-saving on the NIC and set a high-performance power plan: Control Panel > Power Options > choose High performance, and in adapter properties uncheck power-saving options.
Q: Is the USB Ethernet adapter a reliable permanent fix?
A: Good-quality USB 3.0 Ethernet adapters (from reputable vendors) are reliable long-term fixes and useful if the internal NIC is failing or you need an extra port.
In summary, start with physical checks (cable, port, link lights), then verify Windows-level items (adapter enabled, drivers, IP/DNS) and use stack resets (netsh winsock reset, netsh int ip reset) before replacing hardware. The stepwise approach here addresses the most common causes of Ethernet doesn’t work in Windows 10 so you can quickly identify and fix the issue.
