public partial class frm_Painel_de_Producao : Form
{
 frm_Progress_Bar pb = frm_Progress_Bar();

    private async void btnAtualizaGrid_Click(object sender, EventArgs e)
    {

      pb.Show();

      //desabilita os botões enquanto a tarefa é executada.
      btnCancelar.Enabled = false;
      btnIncluir.Enabled = false;
      btnAtualizaGrid.Enabled = false;

      // simply start and await the loading task
      await Task.Run(() => carregarGrid());
      pb.Close();

      // habilita os botões após  tarefa evento de loading.
      btnAtualizaGrid.Enabled = true;
      btnCancelar.Enabled = true;
      btnIncluir.Enabled = true;

    }

 }

public partial class frm_Progress_Bar : Form
{
    public frm_Progress_Bar()
    {
        InitializeComponent();

    }
}

public void carregarGrid()
    {

        timer.Interval = 1000;
        timer.Tick += meuRelogio;
        timer.Start();
        dgvProducao.AutoGenerateColumns = false;
        dgvProducao.DataSource = clsPPCP.painelProducao();
        MeuBD.AbreXML();
        if (MeuBD.RequerUsuario == "1")
        {
            txtOperador.Focus();
        }
        else
        {
            txtOperador.Hide();
            txtNomeOperador.Hide();
            label8.Hide();
            txtCartao.Focus();
        }
        colorirGrid();
        //MeuBDex.AbreXML();
        relogio();
    }