How To get Last System Shut Down Status With Date and Time

private void button1_Click(object sender, EventArgs e)
{
   MessageBox.Show(GetLastSystemShutdown().ToString());
}

public static DateTime GetLastSystemShutdown()
{
   string sKey = @"System\CurrentControlSet\Control\Windows";
   Microsoft.Win32.RegistryKey key = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(sKey);

   string sValueName = "ShutdownTime";
   byte[] val = (byte[])key.GetValue(sValueName);
   long valueAsLong = BitConverter.ToInt64(val, 0);
   return DateTime.FromFileTime(valueAsLong);
}