1   
2   unit Unit1;
3   
4   interface
5   
6   uses
7     Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
8     Dialogs, StdCtrls;
9   
10  type
11    TForm1 = class(TForm)
12      Button1: TButton;
13      procedure Button1Click(Sender: TObject);
14    private
15      { Private declarations }
16    public
17    function IsActiveDeskTopOn:Boolean;
18      { Public declarations }
19    end;
20  
21  var
22    Form1: TForm1;
23  
24  implementation
25  
26  {$R *.dfm}
27  function TForm1.IsActiveDeskTopOn:Boolean;
28  var
29    Hd: HWND;
30  begin
31    Result := False;
32    Hd := FindWindow( Pchar('Progman'), nil);
33    Hd := FindWindowEx( hd, 0, 'SHELLDLL_DefView', nil);
34    Hd := FindWindowEx( hd, 0, 'Internet Explorer_Server', nil);
35    if hd = 0 then
36      Result := False
37    else
38      Result := True;
39  end;
40  
41  
42  
43  procedure TForm1.Button1Click(Sender: TObject);
44  begin
45  if IsActiveDeskTopOn then
46   showmessage('Active Desktop is ON')
47  else
48   showmessage('Active Desktop is OFF');
49  end;
50  
51  end.
52