How to Fix VPN Errors on Windows 11 and Windows 10: Complete and Practical Guide

Connecting to a VPN on Windows 11 or Windows 10 can provide numerous benefits, from improving privacy on public networks to allowing access to geo-restricted content. However, it's not always a smooth road: many users experience Errors when trying to establish a VPN connection, especially after a system update or changes to network settings.

In this comprehensive article we are going to analyze all the known problems, their possible causes, and of course, Practical solutions you can apply to restore VPN access on your deviceWe'll use official information, documented cases, and technical recommendations so anyone, regardless of their skill level, can troubleshoot VPN errors in Windows 11 or 10.

Common VPN Errors on Windows 11 or Windows 10 and Their Causes

The most common errors when trying to connect a VPN on this operating system are accompanied by specific codes or messages like "The connection could not be established" or "The remote server is not responding." Below, we break down the most common ones and what they typically cause.

VPN Error 800

This error indicates that A remote connection could not be established because the attempted VPN tunnels failedThe main causes include:

• Firewall blocking the required port.
• Incorrect login details such as username, password or server IP address.
• Possible interference from malicious programs in the system.

Recommended solutions:

• Verify that the server settings are entered correctly in the Network > VPN section.
• Temporarily disable your antivirus and firewall to see if any of them are blocking the connection.
• Run the network troubleshooter from Settings > Network & Internet.
• Scan your computer with an updated antivirus to rule out malware.

VPN Error 806

This error usually occurs when a VPN application cannot establish communication between the server and the client because something is blocking the GRE (Generic Routing Encapsulation) protocol.

Options to solve it:

• Temporarily stop the firewall and see if the problem goes away.
• Do the same with your antivirus. Make sure it's up to date or consider uninstalling it if it's free or unreliable.
• Open port 1723 in the system firewall.
• Check your computer for threats that are interfering.
• Update both Windows and the router firmware.

VPN Error 809

This error message appears mostly when Windows prevents VPN connection due to NAT settings or because the necessary port is closed.

Resolve error 809 with these steps:

• Modify the Windows registry by adding the value AssumeUDPEncapsulationContextOnSendRule with a DWORD value of 2.
• Allow TCP ports 1723 and UDP 500 or 4500 on the firewall.
• Check that you have entered the username, password, and server correctly in the VPN configuration panel.
• Enable the PAP protocol in the advanced authentication options.
• Avoid using third-party apps that may cause conflicts with your VPN connection.

VPN Error 721 (PPTP)

This error indicates that the remote computer is not responding, generally caused by blocks to the GRE protocol (IP 47), vital for PPTP connections.

Solution: Configure your firewall to allow:

• GRE Protocol (IP 47).
• TCP traffic on port 1723.

Problems with TAP-Windows and virtual adapters

Many VPNs use the TAP-Windows virtual adapter to establish encrypted connections. If this component fails, the VPN will stop working properly.

What to do if TAP-Windows gives errors:

• Restart the adapter from 'Change adapter options' by disabling and enabling it again.
• Reinstall the adapter from Device Manager if it still doesn't work.
• Update Windows to ensure compatibility with TAP.
• In extreme cases, it creates a new TAP adapter from Control Panel > Networks.

Errors after updating Windows 11 or 10

The April 2024 updates (KB5036893 and others) have caused widespread errors that break the VPN connection on many devices.

Affected versions:

• Windows 11 (versions 21H2, 22H2, 23H2)
• Windows 10 (21H2, 22H2)
• All versions of Windows Server from 2008 onwards

How to solve it:

• Uninstall update KB5036893 from your update history.
• Use the DISM command to undo the package: dism /online /remove-package /packagename:NombreDelPaquete.

Please note that removing this update may expose you to vulnerabilities, so proceed with caution.

VPN connected but no internet access

A very common problem is that the VPN connects but You cannot browse the web or use online services.. This may be due to:

• An inadequate VPN protocol or misconfigured.
• DNS problems or incorrect gateway addressing.
• Blocked by firewall or antivirus.

Recommended solutions:

• Make sure your VPN is up to date.
• Change the protocol used by the VPN (PPTP, L2TP, OpenVPN, WireGuard…).
• Try different VPN servers.
• Reset DNS with the command ipconfig /flushdns.
• Ping 8.8.8.8 to verify you can connect to the network.

VPN rejected or connection not established

One of the most frustrating mistakes happens when the VPN directly refuses to connect. This may be due to:

• Incorrect configuration or change of credentials.
• Weak network connection or overloaded VPN server.
• The router you are using does not support VPN or requires an update.
• The firewall is interfering.

DNS errors when using a VPN

In some cases a warning appears indicating a domain name resolution failureThis is usually because the DNS used is not compatible with the VPN.

Steps to fix DNS errors:

• Change the DNS servers in the Network panel. Recommended:
  • Google DNS: 8.8.8.8 and 8.8.4.4
  • Cloudflare: 1.1.1.1 and 1.0.0.1
• Verify that the VPN is correctly installed and configured.
• If the problem persists, change VPN providers.

Advanced VPN Connection Management in Windows

Windows allows export, import, or delete VPN profiles easily. This is useful for migrating settings between computers or cleaning up old profiles.

Export or import a VPN connection:

• Accede to %AppData%\Microsoft\Network\Connections from the browser.
• Copy the folder Pbk and paste it on another computer.
• Manually change the credentials if necessary.

Remove a VPN:

• From Settings > Network & Internet > VPN.
• From the Network and Sharing Center in Control Panel.
• Using commands in PowerShell or CMD (Remove-VpnConnection).

Change password:

• Go to Settings > Network & Internet > VPN.
• Select your connection and click on 'Advanced Options'.
• Change your password and save the changes.

Remember that the key must be complex, safe and uniqueAvoid using the same password as on other services to reduce the risk of leaks.

When nothing works: Reinstall Windows

If after trying all the solutions you still can't use your VPN, there may be a serious system issue, such as broken settings or persistent malware. In this case, format and reinstall windows may be the only reliable way to restore proper functioning.

Performing a clean install also improves overall performance and removes residual files or errors that have been carried over over time, allowing you to start from scratch with the latest versions.

When facing a VPN failure on Windows 11 or 10, it's essential to understand the error code to apply the appropriate solution. Many issues are resolved by adjusting the firewall, changing protocols, reconfiguring the system, or installing updated versions of the affected software. Errors can also be caused by interference from other apps, misconfigured network adapters, or incompatible DNS. Taking preventative measures such as keeping your system updated, using a paid VPN, and avoiding insecure configurations is key to a stable and secure connection.