A Virtual Private Network (or VPN) is a great program for online users who value their online privacy. While VPNs offer some great advantages, however, it isn’t uncommon that users encounter the occasional error. One error that’s been reported on numerous occasions is error 691. The dial-up error occurs when you aren’t on a dial-up connection. When the settings are incorrect on either the server machine or the client, no connection can be verified. Typically, it’s either the username or password that is incorrect. It could also be a result of logging into a public VPN with a domain that it’s allowed, or a mismatch between security protocols.

So, while there’s lots of useful information online about VPNs, here, we’re going to focus specifically on error 691. If you’re getting that particular error, here are a few things you can do.

Make Sure the Login Details Are Correct

This is a basic step, but a necessary one. In fact, it’s the biggest cause of this particular error. So just make sure you’re entering the correct login details, and check Show Password if that option is available. Also, make sure you don’t have CAPS LOCK on.

Change Your Username

The error message can also be a result of the username itself. If your login details are correct but you still see the error, you could try adding the domain name to your username by adding @YourDomainName at the end.

Omit the Domain Name for External Connection

It might be that your VPN works while using your internal network but fails when attempting to connect to an external network. To resolve this issue, omit the domain name for outside connections. Just enter the rest of your login details as normal, and if this was the problem, you should be able to connect without any issues.

Check for Other Active VPNs

Other active VPN connections can also cause the error. To resolve the issue, check your other VPNs to ensure they aren’t running. If you find any that are, disable them, and then check if you’re still getting the error. If you do like to have a third-party VPN installed, make sure you get the best VPN for Windows to minimize the chance of any other problems.

Update Network Drivers

You can do this either through Device Manager or manually. For the second option, you can do this via a third-party tool. Of course, you would need an Internet connection in order to do so. Once you’re online, however, you would be wise to keep your drivers updated so that you’re less likely to see this error. One tool you might want to try is Driver Update from Tweakbit, which has been approved by both Norton and Microsoft. It can also help to prevent any issues to your PC itself by ensuring you don’t have the wrong drivers installed.

Change Your Logon ID

Sometimes, the error can occur as a result of a damaged Login ID. In this case, create a new Logon ID and check if you’re still getting the error.

Remove and Re-add Your VPN Connection

Another thing you can do is remove your VPN connection and re-add it. This isn’t difficult to achieve in Windows 10. You just need to go to Network & Internet in Settings and then the VPN tab. From there, you can remove and add VPNs at will.

Contact Your ISP

Another possibility is that the error has been caused by an issue with your ISP. Some users have stated that this has been the case for them but that they managed to resolve it with their ISP after contacting them.