When working with OpenVPN in Windows environments, you may need to terminate the VPN connection programmatically. Here's the most reliable method:

taskkill /F /IM openvpn.exe

For more controlled disconnection or specific use cases:

# Graceful termination with config file
openvpn --config client.ovpn --verb 0 --down "echo Disconnecting" --down-pre

Create a reusable disconnect script (disconnect_vpn.bat):

@echo off
setlocal
echo Attempting to disconnect OpenVPN...

:: Check if OpenVPN is running
tasklist | find /i "openvpn.exe" >nul 2>&1
if %ERRORLEVEL% equ 0 (
    taskkill /F /IM openvpn.exe
    echo OpenVPN successfully terminated
) else (
    echo No OpenVPN process found
)

endlocal

For system administrators managing multiple machines:

# PowerShell script to monitor and disconnect
Get-Process -Name openvpn* -ErrorAction SilentlyContinue | 
Stop-Process -Force -PassThru |
ForEach-Object { Write-Host "Terminated process ID: $($_.Id)" }

If the standard methods don't work:

• Check for hung processes: tasklist /FI "IMAGENAME eq openvpn.exe"
• Verify TAP adapter status: netsh interface show interface
• Clear DNS cache: ipconfig /flushdns

When working with OpenVPN on Windows, many administrators prefer command-line operations for automation and scripting purposes. While connecting via CLI is straightforward, disconnecting requires specific knowledge of OpenVPN's interface.

The most reliable way to disconnect is through OpenVPN's built-in management interface. First, you need to start OpenVPN with the management interface enabled:

openvpn.exe --config your_config.ovpn --management 127.0.0.1 1194 --management-query-passwords

Once connected, you can send the shutdown command:

echo "signal SIGTERM" | nc 127.0.0.1 1194

For quick disconnection without the management interface, you can terminate the OpenVPN process:

taskkill /IM openvpn.exe /F

Note this is less graceful and might not properly clean up network routes.

Here's a complete batch script example that handles both connection and disconnection:

@echo off
SET CONFIG_PATH="C:\Program Files\OpenVPN\config\your_config.ovpn"
SET MGMT_PORT=1194

:MAIN_MENU
cls
echo OpenVPN Control Panel
echo 1. Connect
echo 2. Disconnect
echo 3. Exit
set /p choice="Enter your choice: "

if "%choice%"=="1" goto CONNECT
if "%choice%"=="2" goto DISCONNECT
if "%choice%"=="3" exit

:CONNECT
start "OpenVPN" /MIN "C:\Program Files\OpenVPN\bin\openvpn.exe" --config %CONFIG_PATH% --management 127.0.0.1 %MGMT_PORT%
goto MAIN_MENU

:DISCONNECT
echo signal SIGTERM | nc 127.0.0.1 %MGMT_PORT%
timeout /t 2 >nul
taskkill /IM openvpn.exe /F >nul 2>&1
goto MAIN_MENU

For more robust control, consider this PowerShell script:

function Disconnect-OpenVPN {
    param (
        [int]$ManagementPort = 1194
    )
    
    try {
        $client = New-Object System.Net.Sockets.TcpClient("127.0.0.1", $ManagementPort)
        $stream = $client.GetStream()
        $writer = New-Object System.IO.StreamWriter($stream)
        $writer.WriteLine("signal SIGTERM")
        $writer.Flush()
        $client.Close()
    }
    catch {
        Write-Warning "Failed to send graceful shutdown signal"
        Get-Process openvpn | Stop-Process -Force
    }
}

Remember that:

• Management interface requires proper authentication if configured
• Hard termination (taskkill) may leave residual network configurations
• Port 1194 is default but may differ in your setup
• Some corporate environments may block raw TCP connections