VB.NET:

Imports System.Security.AccessControl
Imports System.Security.Policy
Imports System.Security.Principal
Imports System.IO
Module Module1Sub Main()
        Dim ds As New DirectorySecurity
        ds.AddAccessRule(New FileSystemAccessRule("Guest", FileSystemRights.Read, AccessControlType.Allow))
        Directory.CreateDirectory("c:\Guest", ds)
        File.Create("c:\Guest\Data.Data")
    End SubEnd Module

C#:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.AccessControl;
using System.Security.Policy;
using System.Security.Principal;
using System.IO;namespace AccessControlListCS
{
    class Program
    {
        static void Main(string[] args)
        {
            DirectorySecurity ds = new DirectorySecurity();
            ds.AddAccessRule(new FileSystemAccessRule("Guest", FileSystemRights.Read, AccessControlType.Allow));
            Directory.CreateDirectory(@"c:\Guest", ds);
            File.Create(@"c:\Guest\Data.Data");
        }
    }
}