Error 651 in Windows

Error 651 in Windows is a common issue that occurs when attempting to connect to the internet via a high-speed connection, typically using PPPoE. This error generally indicates a failure in the modem or network adapter. Below, we’ll go over the main causes of this error and proven ways to resolve it.

Main Causes of Error 651

  • Network adapter configuration conflicts. Sometimes the network adapter driver may malfunction, leading to connection issues.
  • Corrupted or outdated network driver. Damaged or outdated drivers can cause disruptions in connectivity.
  • Modem or router malfunction. Hardware issues with the device can also trigger the error.
  • Incorrect connection settings. In some cases, the error is due to errors in the PPPoE connection setup.

Ways to Fix Error 651

1. Restart Your Computer and Modem

Start with the simplest step—restart your computer and modem or router. This can help clear temporary hardware glitches.

2. Check Cable Connections

Ensure that all cables are connected correctly and that none are damaged. Sometimes a physical connection issue can cause the error.

3. Update the Network Adapter Driver

Updating the network adapter drivers can help fix the issue. To do this:

  1. Press Win + X and select Device Manager.
  2. Locate Network Adapters and select the adapter in use.
  3. Right-click the adapter and choose Update driver.
  4. Follow the on-screen instructions.

4. Reinstall the Network Driver

If updating doesn’t work, try reinstalling the driver:

  1. Open Device Manager as mentioned above.
  2. Right-click on the network adapter and select Uninstall device.
  3. Restart your computer, and Windows will automatically reinstall the driver.

5. Disable IPv6

Sometimes disabling IPv6 can help resolve error 651:

  1. Open Network Connections (press Win + R, type ncpa.cpl, and press Enter).
  2. Right-click on your connection and select Properties.
  3. Uncheck the box for Internet Protocol Version 6 (TCP/IPv6) and click OK.

6. Recreate Your Internet Connection

Try deleting the existing PPPoE connection and setting up a new one:

  1. Open Network Connections.
  2. Right-click on your current connection and select Delete.
  3. Create a new connection following the setup wizard instructions.

7. Check Firewall and Antivirus Settings

Some security programs may block your internet connection. Try temporarily disabling your firewall and antivirus, and check if the connection works.