System.ComponentModel.BackgroundWorker bw = new System.ComponentModel.BackgroundWorker ();

GestionVentana gv = new GestionVentana (ref conf, ref progreso);
bw.RunWorkerCompleted += new System.ComponentModel.RunWorkerCompletedEventHandler
   (gv.bw_RunWorkerCompleted);
bw.DoWork += new System.ComponentModel.DoWorkEventHandler (gv.bw_DoWork);
bw.RunWorkerAsync ();

while (bw.IsBusy)
{
   // O cualquier otra actualización en la interfaz que queramos realizar.
   Application.DoEvents ();
}