uses Registry;
procedure TForm1.Button1Click(Sender: TObject);
var
 reg : TRegistry;
 ts : TStrings;
 i : integer;
begin
 reg := TRegistry.Create;
 reg.RootKey := HKEY_LOCAL_MACHINE;
 reg.OpenKey('hardware\devicemap\serialcomm',
  false);
 ts := TStringList.Create;
 reg.GetValueNames(ts);
 for i := 0 to ts.Count -1 do begin
  Memo1.Lines.Add(reg.ReadString(ts.Strings[i]));
 end;
 ts.Free;
 reg.CloseKey;
 reg.free;
end;