try
using System;
using System.DirectoryServices;
using System.Net;class TestClass
{
static void Main (string[] args)
{
ShowComputers();
}
public static void ShowComputers()
{
                //or use "WinNT://your_domain_name"
DirectoryEntry root = new DirectoryEntry("WinNT:");           DirectoryEntries domains = root.Children;
domains.SchemaFilter.Add("domain");
foreach (DirectoryEntry domain in domains)
{
Console.WriteLine(domain.Name);
DirectoryEntries computers = domain.Children;
computers.SchemaFilter.Add("computer");
foreach (DirectoryEntry computer in computers)
{
Console.WriteLine("\t" + computer.Name);
IPHostEntry iphe = Dns.GetHostByName(computer.Name);
foreach (IPAddress ip in iphe.AddressList)
{
Console.WriteLine("\t\t" + ip);
}
DirectoryEntries users = computer.Children;
}
}
}}