using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.DirectoryServices;
using System.DirectoryServices.AccountManagement;

namespace FindComputersInAD
{
    class Program
    {
        static void Main(string[] args)
        {

            string sDomainName = @"sub.domain.com";//e.g. hk.company.com
            DirectoryEntry de = new DirectoryEntry();
            de.Path = String.Format("LDAP://{0}", sDomainName);
            de.Username = "useraccount";
            de.Password = "password";

            try
            {
                DirectorySearcher ds = new DirectorySearcher();
                ds.Filter = "(&objectCategory=computer)";
                SearchResultCollection results = ds.FindAll();

                foreach (SearchResult result in results)
                {
                    ResultPropertyCollection myResultPropertyCollection = result.Properties;
                    foreach (string myKey in myResultPropertyCollection.PropertyNames)
                    {
                        string propertyString = String.Empty;
                        string tab = "  ";
                        Console.WriteLine("{0} = ", myKey);
                        foreach (Object myCollection in myResultPropertyCollection[myKey])
                        {
                            Console.WriteLine("{0}{1}", tab, myCollection);
                            Console.ReadKey();
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                Console.ReadKey();
            }

        }
    }
}