It is possible that you might have faced error 651 on your computer if you are a Windows user. It is a common problem faced by many Windows users (Especially Windows 10 users). So before we get into the topic, first let’s see why this error occurs.
- 1 Why Error 651 occurs?
- 2 How to Fix Connection Failed with Error 651 in Windows
- 2.1 1 – Reconnect Your Router or Other Connecting Device
- 2.2 2 – Reset TCP/IP On Your PC
- 2.3 3 – Recreating Dial-Up Connection
- 2.4 4 – Disable Auto Tuning Feature
- 2.5 5 – Disable IPv6 of your Internet Connection
- 2.6 6 – Reinstall Network Adapter
- 2.7 7 – Re-register “raspppoe.sys” File
- 2.8 8 – Perform Clean Boot
Why Error 651 occurs?
Error 651 is a common Windows error which usually occurs when we try to establish an internet connection using PPPoE connections. This error occurs due to various reasons such as :
- Raspppoe.sys file has been saved in the wrong location.
- Registry errors.
- IP address conflict.
If this error occurs, then you might see this message Error 651: The modem (or the other connecting device) has reported an error and usually the message will be titled as “Connection failed with error 651”.
So how to solve this error? well, there is no official solution to fix this error, but there are some common troubleshooting methods which worked for many users. I have collected some of the best working solutions that will help you to solve this error.
Also Read – Fix dns_probe_finished_bad_config Error
How to Fix Connection Failed with Error 651 in Windows
1 – Reconnect Your Router or Other Connecting Device
This is the most basic troubleshooting step, One can simply solve this error by reconnecting the internet connecting device. So if you are using router then simply turn off your router and after 5 minutes turn it on or if you are using LAN connection then unplug the wire and plug it back.
2 – Reset TCP/IP On Your PC
Resetting the Windows networking stack can solve error 651 and luckily Windows 8/10 comes with a built-in tool you can use to do this just follow the below steps.
- Launch command prompt with administrative right.
- Copy the command given below and hit enter
netsh int ip reset reset.log
- Restart your computer and hopefully, the problem will be solved.
3 – Recreating Dial-Up Connection
Your internet connecting device might get hanged during the connection. So recreating your dial-up connection can fix this issue. So simply right click your Dial-Up or Broadband connection and select create copy and then delete your existing connection. Confused? Just follow the step by steps guide given below.
- Open Network & Sharing Center and click on Change Adapter Setting.
- Now right click your broadband or dial-up connection and select Create Copy.
- This will create a copy of your existing connection.
- Now simply delete your old connection and redial the new connection.
4 – Disable Auto Tuning Feature
Windows Auto tuning feature is used to improve the performance of programs which receives TCP data from a network. If you are using a router then this method can do the magic, Follow the below steps to disable the auto-tuning feature.
- Launch command prompt with administrative rights.
- Copy the below command and paste it in command prompt
- Now just try to restart/reconnect your internet connection.
5 – Disable IPv6 of your Internet Connection
This solution worked for many users. You can simple disable IPv6 to fix this error. Follow the below guide to disable IPv6.
- Open Control Panel.and select Network & Internet.
- Further, choose the Network & Sharing Center option.
- Now click on your active network connection.
- Select Properties and switch to Networking tab.
- Untick/Uncheck Internet Protocol version 6 (TCP/IPv6) and click on Ok.
6 – Reinstall Network Adapter
This is the most working troubleshooting step when it comes to an internet connection problem. You can simply reinstall the network adapter to fix Connection Failed with Error 651 problem. Just follow the below guide to reinstall network adapter.
- Go to start and search for devmgmt.msc.
- Double click it to launch device manager, Now look for Network Adapters Category and click the “+” icon it’s left.
- Now right click the first network adapter and select uninstall.
- Restart your computer and your network adapter will get automatically reinstalled.
7 – Re-register “raspppoe.sys” File
You may face error 651 due to “raspppoe.sys” file fails to load while connecting to the internet. So to fix this you can try re-registering the raspppoe.sys file.
- Open the command prompt with administrative rights.
- Now type the following command and press enter.
- This command will re-register the raspppoe.sys file which indirectly causes error 651.
8 – Perform Clean Boot
If there is a problem in windows services then performing a clean boot can fix your problem, to perform a clean boot we simply need to disable all other services. Simply follow the below guide to perform a clean boot on your computer.
- Go to start and search for msconfig.exe
- Click it to launch windows configuration.
- Now under general tab click on Selective startup and select Load startup items
- Now switch to Services tab and check Hide all Microsoft services.
- After that just click on Disable all to disable all other services.
- Now simply just restart your pc to perform a clean boot.