public static class HelpFileUtility
{
public static void OpenHelperFileFullScreen(Control control,string fileName)
{
Help.ShowHelp(control, fileName);
control.BeginInvoke(new MethodInvoker(() => HelpFileUtility.MoveHelpWindow(new Rectangle(0, 0, Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height))));

}
public static void MoveHelpWindow(Rectangle rc)
{
EnumThreadWndProc callback = (hWnd, lp) => {
// Check if this is the help window
StringBuilder sb = new StringBuilder(260);
GetClassName(hWnd, sb, sb.Capacity);
if (sb.ToString() != "HH Parent") return true;
MoveWindow(hWnd, rc.Left, rc.Top, rc.Width, rc.Height, false);
return false;
};
foreach (ProcessThread pth in Process.GetCurrentProcess().Threads)
{
EnumThreadWindows(pth.Id, callback, IntPtr.Zero);
}
}
// P/Invoke declarations
private delegate bool EnumThreadWndProc(IntPtr hWnd, IntPtr lp);
[DllImport("user32.dll")]
private static extern bool EnumThreadWindows(int tid, EnumThreadWndProc callback, IntPtr lp);
[DllImport("user32.dll")]
private static extern int GetClassName(IntPtr hWnd, StringBuilder buffer, int buflen);
[DllImport("user32.dll")]
private static extern bool MoveWindow(IntPtr hWnd, int x, int y, int w, int h, bool repaint);
}