unit Unit1;

interface

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

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

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
    reg:TRegistry;
begin
    reg:=TRegistry.Create;
    reg.RootKey:=HKEY_CLASSES_ROOT;
    if reg.OpenKey('*\shell\MyApp',true) then
    begin
        reg.WriteString('','What is this?');
        reg.Closekey;
    end;
    if reg.openkey('*\shell\MyApp\command',true) then
    begin
        reg.WriteString('',Application.Exename+' %1');
        reg.Closekey;
    end;
    reg.free;
end;

procedure TForm1.FormDestroy(Sender: TObject);
var
    reg:TRegistry;
begin
    reg:=TRegistry.create;
    reg.RootKey:=HKEY_CLASSES_ROOT;
    reg.DeleteKey('*\shell\MyApp');
    reg.Free;
end;

end.