How to get the Path to Program files

uses
  Registry;

function GetProgramFilesDir: string;
var
  reg: TRegistry;
begin
  reg := TRegistry.Create;
  try
    reg.RootKey := HKEY_LOCAL_MACHINE;
    reg.OpenKey('SOFTWARE\Microsoft\Windows\CurrentVersion', False);
    Result := reg.ReadString('ProgramFilesDir');
  finally
    reg.Free;
  end;
end;


procedure TForm1.Button1Click(Sender: TObject);
begin
  // Shows something like c:\Program files
 
  ShowMessage(GetProgramFilesDir);
end;