IPsec/L2TP Windows Setup Instructions

Method 1 - Windows 10

Right-click on the notifications icon bottom right.
Click the VPN tab.
Add a VPN connection.
Vpn Provider Choose Windows (built in).
Choose any name at top e.g Server location.
Enter Your VPN Server IP in the Internet address field.
Select L2TP/IPsec with pre-shared key.
Type of sign in, select username and password.
Enter Username & Password.
Tick remember my sign in info.
Then click save.
Then Click on the connection you just setup and click connect
Note: A one-time registry change maybe required before connecting. See details below.

To fix this error, a one-time registry change is required because the VPN server and/or client is behind NAT (e.g. home router). Download and import the .reg file below, or run the following from an elevated command prompt. You must reboot your PC when finished.

For Windows Vista, 7, 8.x and 10 (download .reg file)

REG ADD HKLM\SYSTEM\CurrentControlSet\Services\PolicyAgent /v AssumeUDPEncapsulationContextOnSendRule /t REG_DWORD /d 0x2 /f

For Windows XP ONLY (download .reg file)

REG ADD HKLM\SYSTEM\CurrentControlSet\Services\IPSec /v AssumeUDPEncapsulationContextOnSendRule /t REG_DWORD /d 0x2 /f

Although uncommon, some Windows systems disable IPsec encryption, causing the connection to fail. To re-enable it, run the following command and reboot your PC.

For Windows XP, Vista, 7, 8.x and 10 (download .reg file)

REG ADD HKLM\SYSTEM\CurrentControlSet\Services\RasMan\Parameters /v ProhibitIpSec /t REG_DWORD /d 0x0 /f

Method 2 - Windows 10 and 8.x

Right-click on the wireless/network icon in your system tray.
Select Open Network and Sharing Center. Or, if using Windows 10 version 1709 or newer, select Open Network & Internet settings, then on the page that opens, click Network and Sharing Center.
Click Set up a new connection or network.
Select Connect to a workplace and click Next.
Click Use my Internet connection (VPN).
Enter Your VPN Server IP in the Internet address field.
Enter anything you like in the Destination name field, and then click Create.
Return to Network and Sharing Center. On the left, click Change adapter settings.
Right-click on the new VPN entry and choose Properties.
Click the Security tab. Select "Layer 2 Tunneling Protocol with IPsec (L2TP/IPSec)" for the Type of VPN.
Click Allow these protocols. Check the "Challenge Handshake Authentication Protocol (CHAP)" and "Microsoft CHAP Version 2 (MS-CHAP v2)" checkboxes.
Click the Advanced settings button.
Select Use preshared key for authentication and enter Your VPN IPsec PSK for the Key.
Click OK to close the Advanced settings.
Click OK to save the VPN connection details.

Note: A one-time registry change is required before connecting. See details below.