HideSDesktop.cs

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

namespace Hide
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        [DllImport("user32.dll")]
        static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
        [DllImport("user32.dll", SetLastError = true)]
        static extern IntPtr FindWindowEx(IntPtr hwndParent,
            IntPtr hwndChildAfter, string lpszClass, string lpszWindow);

        private void button1_Click(object sender, EventArgs e)
        {
            IntPtr hWnd = FindWindowEx(IntPtr.Zero, IntPtr.Zero, "Progman", null);
            ShowWindow(hWnd, 0);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            IntPtr hWnd = FindWindowEx(IntPtr.Zero, IntPtr.Zero, "Progman", null);

            ShowWindow(hWnd, 5);
        }
    }
}