unit Unit1;

interface

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

type
TForm1 = class(TForm)
Label1: TLabel;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
hMenuHandle : HMENU;
begin
hMenuHandle := GetSystemMenu(Form1.Handle, FALSE);
if (hMenuHandle <> 0) then DeleteMenu(hMenuHandle, SC_CLOSE, MF_BYCOMMAND);
end;

end.