[Cesar82]

@KaktoR, I think you forgot the begin end.

procedure CurStepChanged(CurStep: TSetupStep);
...
  if (CurStep = ssPostInstall) then
  begin
    if not IsDoneError then
    begin
      #if UseBatch
        if FileExists(ExpandConstant('{#BatchFileName}')) then
        begin
          WizardForm.FilenameLabel.Caption := 'Waiting for batch...';
          Exec2(ExpandConstant('{#BatchFileName}'), '', True);
        end;
      #endif