Windows auto activate method

Question

I need a windows activate method. My code works, but it create a popup window and I don't want it.
Is there any way to activate in background without any message?

private void tryingActivateWindows()
{
    ProcessStartInfo psi = new ProcessStartInfo("cmd", "/c " + "SLMGR -ato");
    psi.UseShellExecute = false;
    psi.CreateNoWindow = true;
    Process p = new Process();
    p.StartInfo = psi;
    p.Start();
    p.WaitForExit();
}

Answer 1

private void tryingActivateWindows()
{
    Process activateScript = new Process();
    activateScript.StartInfo.FileName = @"cscript";
    activateScript.StartInfo.WorkingDirectory = @"C:\Windows\System32\"; 
    activateScript.StartInfo.Arguments = "//B //Nologo slmgr.vbs -ato";
    activateScript.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
    activateScript.Start();
    activateScript.WaitForExit();
}