Error 651 typically occurs when there’s a problem with the connection between your computer and your modem or router. It can appear when using PPPoE connections, like DSL or cable internet. Here are some steps to troubleshoot and fix Error 651:
1. Restart Your Devices
- Restart Your Computer: A simple restart can sometimes resolve the issue.
- Restart Your Modem/Router: Power off your modem and router, wait for about 30 seconds, then power them back on.
2. Check Your Connections
- Cables: Ensure all cables between your computer, modem, and router are securely connected and not damaged.
- Ethernet Ports: Try plugging the Ethernet cable into a different port on your router or computer.
3. Replace the Network Cable
- Faulty Cable: A damaged Ethernet cable can cause connection issues. Replace it with a new or known working cable.
4. Update Network Drivers
- Device Manager: Open Device Manager on your computer, locate your network adapter, right-click on it, and select “Update driver.”
- Manufacturer’s Website: Download the latest drivers from the network adapter or computer manufacturer’s website and install them.
5. Reset TCP/IP Stack
- Command Prompt: Open Command Prompt as an administrator and run the following commands:
sh
netsh int ip reset reset.log
netsh winsock reset
ipconfig /release
ipconfig /renew
ipconfig /flushdns
- Restart Your Computer: After running the commands, restart your computer.
6. Disable IPv6
- Network Connections: Go to Network and Sharing Center, click on “Change adapter settings.”
- Adapter Properties: Right-click on your network connection, select “Properties,” and uncheck “Internet Protocol Version 6 (TCP/IPv6).”
- Restart Your Computer: Restart your computer after making the changes.
7. Recreate the Dial-Up Connection
- Network and Sharing Center: Go to Network and Sharing Center, then click on “Set up a new connection or network.”
- Create a New Connection: Select “Connect to the Internet,” then follow the wizard to set up your connection again.
8. Disable Auto-Tuning Feature
- Command Prompt: Open Command Prompt as an administrator and run the following command:
sh
netsh interface tcp set global autotuninglevel=disabled
- Restart Your Computer: Restart your computer after running the command.
9. Check for Windows Updates
- Windows Update: Ensure your operating system is up to date by checking for and installing any pending Windows updates.
10. Check Modem/Router Firmware
- Manufacturer’s Website: Check if there is a firmware update available for your modem or router on the manufacturer’s website.
- Update Firmware: Follow the instructions provided by the manufacturer to update the firmware.
11. Temporarily Disable Antivirus/Firewall
- Antivirus/Firewall Settings: Temporarily disable your antivirus software and firewall to see if they are causing the issue.
- Test the Connection: If the error goes away, you may need to adjust the settings or switch to different security software.
12. Contact Your ISP
- Service Status: There might be an issue with your Internet Service Provider (ISP). Contact them to check for outages or problems in your area.
- Technical Support: If the problem persists, seek further assistance from your ISP’s technical support team.
By following these steps, you should be able to diagnose and fix Error 651. If the issue persists, it might indicate a more serious problem with your hardware or service provider.