Windows users are very likely to get the Internet connection error 651 when trying to connect Wi-Fi in Windows 7/8/10. If you happen to see an error message like Connection Failed with Error 651, don’t worry, you can fix this problem on your own without asking you tech-savvy friends and buying them meals.

Solution 1 Restart your computer and modem

Except for Error 651, there are lots of connection failure issues that restarting your modem and computer could regain the connection. Please note that waiting for at least 30 seconds after you turn off the power source and unplug the cable.

Solution 2 Use Neptune SystemCare

You can find the System Optimizer tool under System Tuneup tab, choose Select All and then click Optimize. And then see if the connection is back on the game.

Solution 3 Recreate a dial-up connection

If you have a dial-up connection for your network, you can try to create a copy to fix the problem:

1. Right-click the Internet icon at the bottom right corner, and click Open Network and Sharing Center.

2. Click Change adapter settings on the left panel> right-click the dial-up connection> choose Create Copy.

3. Right-click the original dial-up connection, and choose Delete. And then try connecting to the network again to see if it works.

Solution 4 Update your network card driver

The outdated network card driver could disturb Internet connection.

1. Go to Device Manager by right-clicking on the start button and choose Device Manager.

2. Expand the Network adapters and right-click on it to choose Update Driver Software.

These were some methods that can help you fix Connection Failed with Error 651 in Windows.