procedure TForm1.Button1Click(Sender: TObject);
var
  reg : TRegistry ;
  sl : TStringList ;
begin
  reg:=TRegistry.Create ;
  sl:=TStringList.Create ;
  try
    reg.RootKey:=HKEY_LOCAL_MACHINE ;
    if reg.OpenKeyReadOnly('\Software\Microsoft\Windows\CurrentVersion\Time Zones') then
      begin
      reg.GetKeyNames(sl) ;
      Memo1.Lines.Text:=sl.text ;
      end ;
  finally
    sl.free ;
    reg.free ;
    end ;
end;