Active Directory user password expiration date .NET/OU Group Policy

Let me start with http://support.microsoft.com/kb/323750 which contains Visual Basic and VBScript examples and http://www.anitkb.com/2010/03/how-to-implement-active-directory.html which outlines how the maxPwdAge OU setting impacts computers, not users. It also has a comment pointing to AloInfo.exe as a tool from MS that can be used to get password ages.

Here is the example:

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

namespace LDAP
{
    class Program
    {
        static void Main(string[] args)
        {
            string domainAndUsername = string.Empty;
            string domain = string.Empty;
            string userName = string.Empty;
            string passWord = string.Empty;
            AuthenticationTypes at = AuthenticationTypes.Anonymous;
            StringBuilder sb = new StringBuilder();

            domain = @"LDAP://w.x.y.z";
            domainAndUsername = @"LDAP://w.x.y.z/cn=Lawrence E."+
                        " Smithmier\, Jr.,cn=Users,dc=corp,"+
                        "dc=productiveedge,dc=com";
            userName = "Administrator";
            passWord = "xxxpasswordxxx";
            at = AuthenticationTypes.Secure;

            DirectoryEntry entry = new DirectoryEntry(
                        domain, userName, passWord, at);

            DirectorySearcher mySearcher = new DirectorySearcher(entry);

            SearchResultCollection results;
            string filter = "maxPwdAge=*";
            mySearcher.Filter = filter;

            results = mySearcher.FindAll();
            long maxDays = 0;
            if(results.Count>=1)
            {
                Int64 maxPwdAge=(Int64)results[0].Properties["maxPwdAge"][0];
                maxDays = maxPwdAge/-864000000000;
            }

            DirectoryEntry entryUser = new DirectoryEntry(
                        domainAndUsername, userName, passWord, at);
            mySearcher = new DirectorySearcher(entryUser);

            results = mySearcher.FindAll();
            long daysLeft=0;
            if (results.Count >= 1)
            {
                var lastChanged = results[0].Properties["pwdLastSet"][0];
                daysLeft = maxDays - DateTime.Today.Subtract(
                        DateTime.FromFileTime((long)lastChanged)).Days;
            }
            Console.WriteLine(
                        String.Format("You must change your password within"+
                                      " {0} days"
                                     , daysLeft));
            Console.ReadLine();
        }
    }
}

The following code worked for me to get the password expiration date on both domain and local user accounts:

public static DateTime GetPasswordExpirationDate(string userId, string domainOrMachineName)
{
    using (var userEntry = new DirectoryEntry("WinNT://" + domainOrMachineName + '/' + userId + ",user"))
    {
        return (DateTime)userEntry.InvokeGet("PasswordExpirationDate");
    }
}