Please help me, how to Launch External .exe application in the WPF Window.

Below code, I am able to open Notepad.exe and WinWord.exe applications in the WPF window but not other applications.. when i try to open other .exe applications it is opening in separate window. 

```
public partial class Window1 : Window
{
    public IntPtr MainWindowHandle { get; set; }

    [DllImport("user32.dll", SetLastError = true)]
    private static extern long SetParent(IntPtr hWndChild, IntPtr hWndNewParent);

    //[DllImport("user32.dll", SetLastError = true)]
    //private static extern int GetWindowLong(IntPtr hWnd, int nIndex);

    public Window1()
    {
        InitializeComponent();

        try
        {
            //External exe inside WPF Window 
            System.Windows.Forms.Panel _pnlSched = new System.Windows.Forms.Panel();

            WindowsFormsHost windowsFormsHost1 = new WindowsFormsHost();

            windowsFormsHost1.Child = _pnlSched;

            _Grid.Children.Add(windowsFormsHost1);

            //_Grid.Children.Add(_pnlSched);

            ProcessStartInfo psi = new ProcessStartInfo(@"C:\Program Files\Atwin\Atwin2k2.exe");

            psi.WindowStyle = ProcessWindowStyle.Normal;

            Process PR = Process.Start(psi);

            PR.WaitForInputIdle(); // true if the associated process has reached an idle state.

            System.Threading.Thread.Sleep(3000);

            IntPtr hwd = PR.MainWindowHandle;
            SetParent(PR.MainWindowHandle, _pnlSched.Handle);  // loading exe to the wpf window.

        }
        catch (Exception ex)
        { 
            //Nothing...
        }
      }

}

```