unit Unit1;

interface

uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 Dialogs, StdCtrls;

type
 TForm1 = class(TForm)
   Button1: TButton;
   procedure Button1Click(Sender: TObject);
 private
   { Private declarations }
 public
   { Public declarations }
 end;

var
 Form1: TForm1;

implementation

{$R *.dfm}

function MyThread(Parameter: Pointer): Integer; stdcall;
var
hdeskNew, hdeskOld: THandle;
StInfo: TStartupInfo;
PrInfo: TProcessInformation;
begin
hdeskNew:= CreateDesktop('MyDesktop', nil, nil, DF_ALLOWOTHERACCOUNTHOOK, MAXIMUM_ALLOWED, nil);

if hdeskNew <> 0 then begin
  hdeskOld:= GetThreadDesktop(GetCurrentThreadId());
  SetThreadDesktop(hdeskNew);
  SwitchDesktop(hdeskNew);
  MessageBox(0, 'Hello from ''MyDesktop''!', '', MB_OK);

  ZeroMemory(@StInfo, SizeOf(StInfo));
  StInfo.cb:= SizeOf(StInfo);
  StInfo.lpDesktop:= PChar('MyDesktop');
  StInfo.wShowWindow:= SW_SHOW;

  if (CreateProcess(nil, 'notepad.exe', nil, nil, False, 0, nil, nil, StInfo, PrInfo)) then begin
    WaitForSingleObject(PrInfo.hProcess, INFINITE);
    CloseHandle(PrInfo.hProcess);
    CloseHandle(PrInfo.hThread);
  end;
  SwitchDesktop(hdeskOld);
  SetThreadDesktop(hdeskOld);
  CloseDesktop(hdeskNew);
end;
result:= 0;
end;

procedure TForm1.Button1Click(Sender: TObject);
var ThreadId: DWORD;
begin
CreateThread(nil, 0, @MyThread, nil, 0, ThreadId);
end;

end.