When an L2TP/IPSec VPN connection on Windows 7 fails with error 809 and external websites become unreachable after connecting, the problem is not always solved by registry changes alone. In this case, the fix required both registry edits and making sure several related services were actually running.

The first step was to add the following registry entry:

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\RasMan\Parameters]
"ProhibitIpSec"=dword:00000000

After that, the connection still returned error 809, so another registry value had to be added:

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\PolicyAgent]
"AssumeUDPEncapsulationContextOnSendRule"=dword:00000002

Even with both entries in place, the VPN still would not work. The real issue turned out to be that three Windows services needed to be started:

• Remote Access Auto Connection Manager
• Remote Access Connection Manager
• Secure Socket Tunneling Protocol Service

After checking the system, Remote Access Auto Connection Manager was set to Manual and was not running. Changing it to start automatically fixed the problem. Once that was done, the L2TP/IPSec VPN connected normally, and access to external websites also worked again.

In practice, the complete solution was:

1. Add both registry entries above.
2. Set the three related services to start automatically.
3. Restart the computer.
4. Reconnect to the VPN.

That was enough to restore normal operation.

The registry changes were still necessary here because an IPSec key was being used. Without a key, using L2TP would lose much of its purpose. So for this setup, both the registry configuration and the service startup settings mattered.

This was similar to configuring the same type of connection on Windows 10. Although some people say Windows 7 is simpler, in actual use the process was nearly the same: adjust the registry, check the services, and reboot before testing again. A local network VPN connection also worked normally after the changes, which confirmed that the setup itself was valid.

Below are the local network speed comparison images.

With VPN:

Direct LAN connection:

On a local network, the speed difference was very small, within about 0.5%. L2TP performance was acceptable in this environment. A remote network test would be needed for a more meaningful comparison.