System.Diagnostics.Process.Start

StreamWriter sw;
private void button1_Click(object sender, EventArgs e)
{
sw = File.CreateText("C:\\Zm1.html");
sw.WriteLine("HTML>HEAD>TITLE>/TITLE>/HEAD>");
sw.WriteLine("BODY>H1>HELLO/H1>/BODY>");
sw.WriteLine("/HTML>");
sw.Close();
}

private void button2_Click(object sender, EventArgs e)
{

System.Diagnostics.Process.Start("iexplore", "C:\\Zm1.html");
}
}