DirectoryEntry localMachine = new DirectoryEntry("WinNT://" +
    Environment.MachineName);
            DirectoryEntry newUser = localMachine.Children.Add("localuser", "user");
            newUser.Invoke("SetPassword", new object[] { "3l!teP@$$w0RDz" });
            newUser.CommitChanges();
            Console.WriteLine(newUser.Guid.ToString());
            localMachine.Close();
            newUser.Close();