Error 651 :The Modem (Connecting Device) has Reported an Error

Updated by: Alex George on June 09, 2025

Today, while connecting my laptop to the internet, I received an error message: Error 651 – The Modem (or Other Connecting Device) Has Reported an Error.

I used a USB modem to connect my Windows 11 laptop to the internet.

The Network Connection prompt gives me the option to either redial or cancel. I chose to redial but received the same Error 651 message again.

Let me share a screenshot of the error.

651 :The Modem (or other Connecting Device) has Reported

I have updated this article with inputs from a few clients and reads of CoreNetworkZ Tech Solutions.

Let me share one comment.

Sam Britto, a client of CoreNetworkZ Tech Solutions, asked, "My HP laptop shows the connection failed with error 651. Is error 651 a broadband connection error? Can I follow this guide?"

In this tutorial, I will share how I resolved Error 651 – The Modem (or Other Connecting Device) Has Reported an Error message.

Reasons for Receiving Error 651

Initially, I checked the Microsoft Knowledge Base for a solution. According to their documentation, Error 651 – The Modem (or Other Connecting Device) Has Reported an Error related to the Layer 2 Tunneling Protocol (L2TP).

They explain that the issue occurs because "the Layer 2 Tunneling Protocol (L2TP) tries to create a host route and then detects that the route to the host, which was by the dial-up connection, already exists."

However, I am unsure if this explanation applies to my situation because I found this answer under Windows 2000. There, the error message seems related to establishing a VPN connection.

So, I could not find the exact reason from Microsoft documentation. That means I had to do extra research.

One of the most frequently mentioned reasons for Error 651 is an issue with the raspppoe.sys file in Windows 7. Many users on support forums have reported that replacing the Windows 7 raspppoe.sys file with the version from Windows Vista helped resolve the issue.

But none of them suggested anything about Windows 11. So, I skipped it.

Arun Kumar, a PHP developer from Cochin, asked, "What do you think Alex? Can we fix this issue by replacing raspppoe.sys file?"

I have never tried this method, so I cannot confirm whether it works. However, if the solution outlined in this tutorial does not work for you, this workaround is worth considering.

Practical Steps to Resolve "Error 651 – The Modem (or Other Connecting Device) Has Reported an Error"

Let me explain how I fixed this issue on my laptop. If you encounter Error 651, follow these steps in the given order:

  1. Click the Redial button to attempt reconnection. If it does not work, I suggest you try the second step.

  2. Unplug the modem and reconnect it (for external and USB modems).

  3. Reboot your computer.

  4. Use an Administrator account to connect to the internet.

  5. Remove all Dial-up Network connections

    Aleena Xavio, a reader of CoreNetworkZ Tech Solutions, asked in the comments, "Hello Alex, I do not know how to check if my Windows 11 Dell laptop has predefined dial-up connections. Can you tell me from where I can check it?"

    To remove a dial-up network connection, navigate to:-

    Control Panel > Network and Internet > Network Connections

  6. Ensure that you are using the latest modem driver.

  7. The last solution needs high technical knowledge. I suggest you take assistance from an expert before doing it.

    This step requires high technical skills.

    Replace the raspppoe.sys file with the version from the working Windows 11 (if applicable).

You can find the raspppoe.sys file in the following directory:

C:\Windows\System32\drivers

Author: Alex George

Author

Alex George is the Chief Editor and founder of CoreNetworkZ Tech Solutions. He is a senior software developer with 20 years of experience.

You can contact him at alex.george@corenetworkz.com.

3 comments:

  1. Joel Mathew4:32 PM

    Thank you. It fixed the problem on my laptop.

    ReplyDelete
  2. Pinky sharma4:32 PM

    Wonderful guide. Thank you , it saved my day.

    ReplyDelete
  3. P K Ramdas4:33 PM

    I appreciate your help, ALex George. It worked.

    ReplyDelete

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