Running a method in BackGroundWorker and Showing ProgressBar

What I want is when some method is doing some task UI keeps itself active and I want to show the progress of the work in a progress-bar.

I have a method, a BackGroundWorker and a Progressbar. I want to call the method when BackGroundWorker starts running and show the progress. The method contains a loop. So, it can report the progress.

So, what can be done?

private void Form1_Load(object sender, EventArgs e)
{
    // TODO: This line of code loads data into the 'dataSet1.TBLMARKET' table. You can move, or remove it, as needed.
    myBGWorker.WorkerReportsProgress = true;
}

private void myBGWorker_DoWork(object sender, DoWorkEventArgs e)
{
    parseFiles();
}

private void myBGWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    myProgressBar.Value = e.ProgressPercentage;
}

private void myBGWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    MessageBox.Show("Done");
}

private void parseButton_Click(object sender, EventArgs e)
{
    myBGWorker.RunWorkerAsync();
}

public void parseFiles()
{
  for()
  {
     //parsing
     myBGWorker.ReportProgress(...);
  }
}

But it's not working. The Progressbar is not updating. Only a small progress is showing after the MessageBox "Done".