C#

Process.Start("shutdown", "-s");

void OnButtonClick(object sender, EventArgs e)
{
     Form1 form1 = new Form1();
     form1.Show();
     //Some more code that I don't think you need to see
}

private void btnShutDown_Click(object sender, EventArgs e)
        {
            string t = "-r -c \"I am going to reboot your mechine\" -t 20";
            Process process = new Process();
            process.StartInfo.FileName = "shutdown.exe ";
            process.StartInfo.Arguments = "-l";
            process.Start();
        }

public static class UserDetails
{
   public static string name;
   public static string dob;
}