Troubleshooting VPN errors on Windows 10 and 11 computer is something that can help you successfully avoid any inconveniences in the future. To successfully keep yourself safe, you should be aware of the possible issues that you may frequently encounter.
In this article, we’ve decided to cover three Windows 10 or 11 PC VPN connection errors that are quite prominent. These include Error 691, 812 and 628. These errors are mainly related to incorrect verification details, modem issues and a failed authentication.

How to Troubleshoot and Fix VPN Error 691 on Windows 10 or 11 Computer
As this PC VPN service issue is related to your login and password, the solutions involve verifying your details, or making some changes to certain parameters.
The error message that appears on the screen looks something like this:
"Error 691: The remote connection was denied because the user name and password combination you provided is not recognized, or the selected authentication protocol is not permitted on the remote access server."
Check your Username and Password
On Windows 10, there can sometimes be a discrepancy between login details of a VPN server. Be sure to avoid using your CAPS keys if they are not required for your password details.
Correct your Connection Security Settings to Fix VPN Error 691 on Windows 10/11 PC
- Press Windows + X key
- Click on your Network Connections
- Locate your connection and right-click on it and go to Properties
- Click on Security
- Select your Typical (recommended settings)
- Under the Validate my identity as follows option, select Allow unsecured password
- Head over to Options and uncheck the Include Windows Logon domain option if it is checked
- Click on OK
How to Fix Error Code 812 with VPN Connections on Windows 10/11
This error code is relatively common as it relates to server connections on Windows PCs. When your Server Network Policy and Client Connection Profile are not in sync with the authentication profile, you may encounter this VPN error. There are also other reasons why it may pop up and this error message show on the screen:
"Error 812: The connection was prevented because of a policy configured on your RAS/VPN server. Specifically, the authentication method used by the server to verify your username and password may not match the authentication method configured in your connection profile. Please contact the Administrator of the RAS server and notify them of this error. If you continue to receive error messages, you can enable logging for analysis."

Change your DNS Settings on PC
After encountering this error, it might be time to change your Primary DNS to your Domain Controller
- Go to Control Panel
- Head over to your Network and Sharing Center and click on Change adapter settings
- Select the connection you wish to edit
- Go to the Networking tab
- Click on Advanced and select the DNS tab
- Click on OK
- Select use the following DNS server addresses and use the Google DNS addresses
How to Fix VPN Error 628 on Windows 10 or 11 PC
This error is directly related to your router or modem, and not your computer itself. The error message states “Error 628: The connection was terminated by the remote computer before it could be completed.”

Here is what you need to do to fix the problem.
Narrow Down the Source of the VPN Connection Error on your Windows 10/11 PC
The first thing you need to do while troubleshooting a problem like this is to track down its orign. Here’s how you do that:
- Boot your Windows computer in Safe mode with networking, then turn on your VPN Connection and see if the issue occurs
- Check your Windows firewall settings and ensure that your port used by the VPN is not blocked
- Bypass your router if it connected to one
- Check if other computers in your network can establish a connection with the VPN
Depending on your findings, you should be able to know whether resetting your router or changing your VPN provider is the appropriate solution. The right fix might even end up as something completely different.
Wrapping Up!
The Windows 10 and 11 VPN experience is something that is completely unique in terms of experience. The reason for an error and the proper fix is not always set in stone, but if you’re willing to pay close attention to the details, troubleshooting these problems is not impossible.