File Manager using C# and Multithreading

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace FileManager
{
    public partial class process : Form
    {
        public process()
        {
            InitializeComponent();
        }

        public void update_progress()
        {
            if (progressBar1.Value >= progressBar1.Maximum)
            {
                progressBar1.Value = progressBar1.Minimum;
            }
            progressBar1.Value += 5;
            this.Refresh();
            return;
        }
    }

}