Edit_Hosts_File

using System;
using System.IO;
using System.Windows.Forms;

namespace Edit_Host
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                using (StreamWriter sw = File.AppendText(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.System), @"drivers\etc\hosts")))
                {
                    sw.WriteLine("127.0.0.1 websiteDomaine");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
    }
}