protected override void WndProc(ref Message m)
        {
            if (m.Msg == Native.WM_DEVICECHANGE)
            {
                if(aktiv)
                switch (m.WParam.ToInt32())
                {
                    //
                    // New device has just arrived
                    //
                    case Native.DBT_DEVICEARRIVAL:
                        label1.Text = "USB entdeckt";
                        progressBar1.Value = 0;
                        Application.DoEvents();
                        LoadItems();
                        break;
                    //
                    // Device is about to be removed
                    // Any application can cancel the removal
                    //
                    case Native.DBT_DEVICEQUERYREMOVE:
                        break;
                    //
                    // Device has been removed
                    //
                    case Native.DBT_DEVICEREMOVECOMPLETE:
                        label1.Text = "Stick kann entnommen werden.";
                        Application.DoEvents();
                        LoadItems();
                        break;
					case 7: // kommt öfter hat scheinbar keine genaue Bedeutung
                    default:
                        break;
                }
            }
            base.WndProc(ref m);
        }

        bool DisableAutoplay = false;
        public Form1()
        {
            InitializeComponent();
            RegistryKey mk;
            if (GetRegKeyByFullName(@"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\AutoplayHandlers", out mk, true))
            {
                object value = mk.GetValue("DisableAutoplay");
                if (value == null)
                {
                    mk.SetValue("DisableAutoplay", 1);
                    DisableAutoplay = true;
                }
            }

...
...
...
        }


// müsste noch erweitert werden. Wenn man an einen Key gerät, an den man nicht dran darf ist es nützlich.
        bool GetRegKeyByFullName(string name, out RegistryKey retValue, bool auchSchreiben)
        {
            retValue = null;
            int pos1 = name.IndexOf("\\");
            string region = name.Substring(0, pos1);
            name = name.Substring(pos1 + 1);
            switch (region)
            {
                case "HKEY_LOCAL_MACHINE":
                    try
                    {
                        retValue = Registry.LocalMachine.OpenSubKey(name,auchSchreiben);
                        return true;
                    }
                    catch (Exception)
                    {
                        return false;
                    }
                case "HKEY_CURRENT_USER":
                    try
                    {
                        retValue = Registry.CurrentUser.OpenSubKey(name, auchSchreiben);
                        return true;
                    }
                    catch (Exception)
                    {
                        return false;
                    }
                default:
                    break;
            }
            return false;
        }



        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (DisableAutoplay)
            {
                RegistryKey mk;
                if(GetRegKeyByFullName(@"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\AutoplayHandlers", out mk, true))
                    mk.DeleteValue("DisableAutoplay");               
            }
        }