How do I troubleshoot my ethernet cable?

Question

How do I troubleshoot my ethernet cable?

James 0

Recently, my PC has been unable to connect to the Internet via ethernet. This is strange, as it was working brilliantly less than an hour before, then when I start up my PC, I have no Internet. I have changed cables, tried powershell commands, restarted the router and powered off powerline adapters. Nothing seems to work. My indicator light at the back of my PC next to the port is flashing orange/red, regardless of which cable I put in. Please, if anyone has any ideas how to fix this, please do respond.

Bulldog 2,310 Reputation points

2026-01-27T20:58:34.69+00:00

Actually, you don't connect to the internet via Ethernet - you connect to your router via Ethernet (or WiFi as the case may be.) Your router connects to the Internet with its own Ethernet cable or a coaxial cable, depending on your setup. So you are dealing with two separate networks: an internal network consisting of your router and the devices that connect to it, which is also known as a local area network or LAN; and an external network which begins at your router and goes out to the Internet. This is also known as a wide area network or WAN.

The indicator light on your computer's Ethernet port tells you whether your computer is connected to your LAN. If it's flashing red, it's not connected to your LAN, which is to say it's offline. So when troubleshooting, keep in mind that you're looking for a problem with your LAN.

If you enjoy getting into the networking weeds, it would be fun to run diagnostic steps. But honestly, if you just want to get your computer back online, the easiest way to do that is to setup your LAN according to the directions in your router's instruction manual. Fortunately, an Ethernet connection is one of the easier tasks in computing, as long as you follow the directions. No fancy commands or configurations are needed. The only maintenance a home user's LAN needs is to occasionally restart the router, which clears the router's internal caches. Best wishes for your success.
James 0 Reputation points

2026-01-28T08:03:52.3733333+00:00

Hi, thank you for your response, it has come to the conclusion that I recently updated my PC and I believe this almost certainly has something to do with the problem, I will uninstall it and see if anything changes, thank you.

4 answers

Your answer

Bulldog 2,310 Reputation points

2026-01-27T20:58:34.69+00:00

Actually, you don't connect to the internet via Ethernet - you connect to your router via Ethernet (or WiFi as the case may be.) Your router connects to the Internet with its own Ethernet cable or a coaxial cable, depending on your setup. So you are dealing with two separate networks: an internal network consisting of your router and the devices that connect to it, which is also known as a local area network or LAN; and an external network which begins at your router and goes out to the Internet. This is also known as a wide area network or WAN.

The indicator light on your computer's Ethernet port tells you whether your computer is connected to your LAN. If it's flashing red, it's not connected to your LAN, which is to say it's offline. So when troubleshooting, keep in mind that you're looking for a problem with your LAN.

If you enjoy getting into the networking weeds, it would be fun to run diagnostic steps. But honestly, if you just want to get your computer back online, the easiest way to do that is to setup your LAN according to the directions in your router's instruction manual. Fortunately, an Ethernet connection is one of the easier tasks in computing, as long as you follow the directions. No fancy commands or configurations are needed. The only maintenance a home user's LAN needs is to occasionally restart the router, which clears the router's internal caches. Best wishes for your success.
James 0 Reputation points

2026-01-28T08:03:52.3733333+00:00

Hi, thank you for your response, it has come to the conclusion that I recently updated my PC and I believe this almost certainly has something to do with the problem, I will uninstall it and see if anything changes, thank you.

Answer 1

Horace Wiggins 440

Check the Control Panel and see if Ethernet is selected.

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James 0 Reputation points

2026-01-28T08:06:23.6433333+00:00

Hello, thank you for your response, I did take this step while troubleshooting, but I believe a windows update has caused this problem.

Answer 2

franco d'esaro 24,991 Volunteer Moderator

Hi James.

If possible, connect your PC directly to a LAN port on your router and see if you can access the internet. If so, reset both Powerline devices and then try again.

0 comments

Answer 3

EmilyS726 239.1K Independent Advisor

Hi James,

On the modem/router itself, it typically also has indicator light for internet connection. Have you checked to make sure that internet is on on the modem/router?

What do you have for internet service provider? You can also give them a call. These days they can typically check modem/router connection status remotely. For example, I have Spectrum. I can go to my Spectrum app to look at my connection and modem status. If it is not connected, you don't even need to check anything beyond the modem as it is either the modem or something between the modem and your service.

James 0 Reputation points

2026-01-28T08:05:09.29+00:00

Thanks for the response, before calling my ISP, I figured this was a problem with windows itself, I remembered I recently updated my PC, this will likely the cause of the issue.
EmilyS726 239.1K Reputation points Independent Advisor

2026-01-28T13:18:02.67+00:00
Turn off the computer, unplug the computer from the power cord, then hold down the power button for 30 seconds. Turn the computer back on to see if it works.

If not, Can you share with me two screenshots please?

Go to Device Manager > Network Adapters, I would like to see what's listed.

Please type msinfo32.exe in the search on the taskbar and hit enter, then share a screenshot of the pop up.

Thanks!

Answer 4

To troubleshoot your Ethernet connection issue, you can follow these steps:

Check Network Adapter: Ensure that your network adapter is working properly. You can do this by going to Device Manager, expanding the Network adapters section, and checking if there are any warning signs (like a yellow exclamation mark) next to your Ethernet adapter. If there are issues, you might need to uninstall the adapter and let Windows reinstall it automatically.
Verify Physical Connections: Make sure that the Ethernet cable is securely connected to both your PC and the router. If the indicator light is flashing orange/red, it could indicate a problem with the connection.
Reset Network Settings: You can reset your network settings to restore default configurations. This can be done using the following commands in PowerShell:
```
   netsh int ip reset
   netsh winsock reset
```
After running these commands, restart your PC.
Test with Another Device: If possible, connect another device using the same Ethernet cable and port to see if it can access the Internet. This will help determine if the issue is with your PC or the network itself.
Check Router Settings: Sometimes, router settings can affect connectivity. Ensure that the router is properly configured and that there are no restrictions on the Ethernet port you are using.
Inspect for Hardware Issues: If none of the above steps work, there may be a hardware issue with your network adapter or the router. Consider testing with a different Ethernet adapter or router if available.

By following these steps, you should be able to identify and potentially resolve the issue with your Ethernet connection.

References:

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How do I troubleshoot my ethernet cable?

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