About ACL control.

reference : http://blog.crowe.co.nz/archive/2007/08/25/c---An-example-of-setting-NTFS-Directory--File.aspx

using System.IO;
using System.Security.AccessControl;

namespace Bruce.Lib
{
    public class DirectoryPermissions
    {
        private static void Main(string[] args)
        {
            string ADDomain = "Domain";
            string ADUser = "Chris";
            string Path = @"c:\temp\chris";

            if (Directory.Exists(Path) == false)
                Directory.CreateDirectory(Path);

            // Remove any inheritable permissions from the path 
            RemoveInheritablePermissons(Path);

            // Add the access control entries for the path 
            AddDirectorySecurity(Path, ADDomain + "\\" + ADUser, FileSystemRights.Modify,
                                 InheritanceFlags.ContainerInherit | InheritanceFlags.ObjectInherit,
                                 PropagationFlags.None, AccessControlType.Allow);
            AddDirectorySecurity(Path, ADDomain + "\\Domain Users", FileSystemRights.Delete, InheritanceFlags.None,
                                 PropagationFlags.None, AccessControlType.Deny);
            AddDirectorySecurity(Path, ADDomain + "\\Domain Admins", FileSystemRights.FullControl,
                                 InheritanceFlags.ContainerInherit | InheritanceFlags.ObjectInherit,
                                 PropagationFlags.None, AccessControlType.Allow);
        }


        // Adds an ACL entry on the specified directory for the specified account. 
        public static void AddDirectorySecurity(string FileName, string Account, FileSystemRights Rights,
                                                InheritanceFlags Inheritance, PropagationFlags Propogation,
                                                AccessControlType ControlType)
        {
            // Create a new DirectoryInfo object. 
            DirectoryInfo dInfo = new DirectoryInfo(FileName);
            // Get a DirectorySecurity object that represents the  
            // current security settings. 
            DirectorySecurity dSecurity = dInfo.GetAccessControl();
            // Add the FileSystemAccessRule to the security settings.  
            dSecurity.AddAccessRule(new FileSystemAccessRule(Account,
                                                             Rights,
                                                             Inheritance,
                                                             Propogation,
                                                             ControlType));
            // Set the new access settings. 
            dInfo.SetAccessControl(dSecurity);
        }

        // Removes an ACL entry on the specified directory for the specified account. 
        public static void RemoveDirectorySecurity(string FileName, string Account, FileSystemRights Rights,
                                                   AccessControlType ControlType)
        {
            // Create a new DirectoryInfo object. 
            DirectoryInfo dInfo = new DirectoryInfo(FileName);
            // Get a DirectorySecurity object that represents the  
            // current security settings. 
            DirectorySecurity dSecurity = dInfo.GetAccessControl();
            // Add the FileSystemAccessRule to the security settings.  
            dSecurity.RemoveAccessRule(new FileSystemAccessRule(Account,
                                                                Rights,
                                                                ControlType));
            // Set the new access settings. 
            dInfo.SetAccessControl(dSecurity);
        }

        // Removes an ACL entry on the specified directory for the specified account. 
        public static void RemoveInheritablePermissons(string FileName)
        {
            // Create a new DirectoryInfo object. 
            DirectoryInfo dInfo = new DirectoryInfo(FileName);
            // Get a DirectorySecurity object that represents the  
            // current security settings. 
            DirectorySecurity dSecurity = dInfo.GetAccessControl();
            // Add the FileSystemAccessRule to the security settings. 
            const bool IsProtected = true;
            const bool PreserveInheritance = false;
            dSecurity.SetAccessRuleProtection(IsProtected, PreserveInheritance);
            // Set the new access settings. 
            dInfo.SetAccessControl(dSecurity);
        }

    }
}