C# make application inside application

create a win 32 form, add a panel named panel1 and use this code. this will not work on directx calls. form, namespace, and panel are depends on your project's name

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Diagnostics;
using System.Threading;
using System.Runtime.InteropServices;

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {

        [DllImport("user32.dll", SetLastError = true)]
        private static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);
        [DllImport("user32.dll", EntryPoint = "SetWindowPos")]
        public static extern IntPtr SetWindowPos(IntPtr hWnd, int hWndInsertAfter, int x, int Y, int cx, int cy, int wFlags);
        public Form1()
        {
            InitializeComponent();
        }

        private void LoadApplication(string path, IntPtr handle)
        {
            Stopwatch sw = new Stopwatch();
            sw.Start();
            int timeout = 10 * 1000;     // Timeout value (10s) in case we want to cancel the task if it's taking too long.

            Process p = Process.Start(path);
            while (p.MainWindowHandle == IntPtr.Zero)
            {
                System.Threading.Thread.Sleep(10);
                p.Refresh();

                if (sw.ElapsedMilliseconds > timeout)
                {
                    sw.Stop();
                    return;
                }
            }

            SetParent(p.MainWindowHandle, handle);      // Set the process parent window to the window we want
            SetWindowPos(p.MainWindowHandle, 0, 0, 0, 0, 0, 0x0001 | 0x0040);       // Place the window in the top left of the parent window without resizing it
        }

        private void panel1_Paint(object sender, PaintEventArgs e)
        {
            LoadApplication(@"notepad.exe", this.Handle);
        }
    }
}