Process Bar

I want to include a Process Bar  (for background process) so that when user click the button the process Bar starts and finishes when program stops
  private void button4_Click(object sender, EventArgs e)
{

File.AppendAllLines(@"C:\Delta Sigma\Log.txt", new string[1] {"Critical Delta Sigma:" +textBox1.Text });


File.AppendAllLines(@"C:\Delta Sigma\Log.txt", new string[1] { "Non Critical Cpk :" + textBox2.Text });


File.AppendAllLines(@"C:\Delta Sigma\Log.txt", new string[1] { "Critical Cpk:" + textBox3.Text });



Thread t = new Thread(GoCompare);
t.IsBackground = true;
t.Start();




}