How To Fix Ethernet Speed Capped At 100 Mbps On Windows

If your Ethernet connection is capped at 100 Mbps despite having a gigabit-capable setup, there are several steps you can take to resolve this issue on Windows. Here’s a comprehensive guide to help you troubleshoot and fix the problem.

Ensure Proper Cable Connections

The first step is to ensure that your Ethernet cables are properly connected. Sometimes, a loose or partially connected cable can cause the speed to drop to 100 Mbps. Here’s how to check:

• Disconnect and Reconnect: Disconnect the Ethernet cable from both your router and computer. Wait for about 30 seconds and then reconnect it. Ensure that the cable is tightly connected at both ends. A loose connection can be eliminated by pushing the cable all the way into the LAN port even if the clip is broken.

Check Ethernet Cable

The quality and type of Ethernet cable can significantly impact your connection speed. Here are some points to consider:

• Cable Type: Ensure you are using a cable that supports gigabit speeds, such as Cat 5e, Cat 6, or Cat 8. Using a lower-grade cable can limit your speed to 100 Mbps.
• Cable Condition: Check for any physical damage to the cable. If the cable is damaged, replace it with a new one.

Replace RJ45 Connectors

If the RJ45 connectors on your Ethernet cable are damaged or loose, it can affect the connection speed. Here’s what you can do:

• Inspect Connectors: Check the RJ45 connectors for any signs of damage or wear. If they are damaged, consider replacing the connectors or the entire cable.

Check Ethernet Adapter Settings

Incorrect settings on your Ethernet adapter can cap your speed at 100 Mbps. Here’s how to check and adjust these settings:

• Open Network Connections:
  • Search for and open the Settings app from Windows Search.
  • Select “Network & Internet” from the options on the left, then “Advanced network settings” on the right pane.
  • Click “More network adapter options” under “Related settings.”
  • In the new window titled “Network Connections,” right-click your Ethernet adapter and click “Properties”.
• Configure Speed & Duplex:
  • In the Properties window, click the “Configure” button to open additional properties.
  • Open the “Advanced” tab at the top and select “Speed & Duplex” from the “Property” box.
  • Ensure that the value on the right is set to “Auto Negotiation.” This setting allows your computer to negotiate the maximum speed possible based on your broadband plan and Ethernet cable. Avoid setting it to “1.0 Gbps Full Duplex” unless absolutely necessary, as “Auto Negotiation” is the recommended setting.
• Disable Power-Saving Features:
  • Ensure that settings like “Energy-Efficient Ethernet,” “Gigabit Lite,” “Green Ethernet,” and “Power Saving Mode” are set to “Disabled” to prevent them from limiting your Ethernet speed.

Update Ethernet Drivers

Outdated Ethernet drivers can cause a variety of issues, including capped speeds. Here’s how to update your drivers:

• Open Device Manager:
  • Right-click the Windows icon and select “Device Manager.”
  • Under “Network adapters,” right-click the name of your Ethernet adapter and click “Update driver”.
• Search for Drivers:
  • Select “Search automatically for drivers” and let Windows search for the latest network drivers for your adapter.
  • If available, new drivers will be installed automatically. If not, you’ll see the message: “The best drivers for your device are already installed”.

Check Router Settings

Sometimes, the issue might be with your router settings. Here are some steps to check:

• Check QoS Settings: Some routers have Quality of Service (QoS) settings that might be limiting your speed to 100 Mbps. Check your router settings to see if QoS is enabled and adjust it accordingly.
• Use Gigabit-Capable Ports: Ensure that you are using a gigabit-capable port on your router or switch. If the port is only capable of 100 Mbps, it will limit your speed.

Additional Troubleshooting

If the above steps do not resolve the issue, here are some additional troubleshooting steps:

• Try Different Ports: If possible, try connecting your Ethernet cable to a different port on your router or switch to rule out any issues with the specific port.
• Check for Hardware Issues: If you have tried all the above steps and the issue persists, it might be a hardware issue. Check if the problem occurs when connecting to a different device or network to isolate the issue.

By following these steps, you should be able to identify and fix the issue causing your Ethernet speed to be capped at 100 Mbps on Windows.