Problem with ProgressBar

private bool CopyingWithProgressBar(ArrayList myAl)
        {
            bool result = true;
            try
            {
                Object[] helpArr = myAl.ToArray();
                pBar1.Visible = true;
                pBar1.Minimum = 0;
                pBar1.Maximum = helpArr.Length;
                pBar1.Value = 1;
                pBar1.Step = 1;

                for (int x = 0; x < helpArr.Length; x++)
                {
                    string input = helpArr[x].ToString().Substring(0, helpArr [x].ToString().IndexOf(","));
                    string target = helpArr[x].ToString().Substring(helpArr [x].ToString().IndexOf(",") + 1);
                    File.Copy(input, target, true);
                    Thread.Sleep(100);
                    pBar1.PerformStep();


                }
                myAl.Clear();
                myAl.TrimToSize();
                myAl = null;
                helpArr= null;
            }
            catch (Exception ex)
            {
                MessageBox.Show("Some Problems with copy." + ex.Message, "Error.", MessageBoxButtons.OK,
                    MessageBoxIcon.Error);
                result = false;
            }
            return result;
        }