If you have a small portal at work and need to provide a way for people to reset their password(s) or have certain authorized people reset password(s), here is a easy solution. In addition to the password reset, I also unlock the account since they have probably locked the account from trying to log in with the wrong password a million times!

Before you start, you need to know a few things first. Use Microsoft’s Active Directory Users and Computers (“ADUC”) Administrator tool on a Domain Controller to find these facts.

  1. Domain Name (ADUC)
    e.g. microsoft.local and MICROSOFT
  2. Domain Controller Name (ADUC, look under Domain Controllers)
  3. User Container (e.g. Item where all your users are located, default is “Users”)

In the example below, the company local domain is “MICROSOFT.COM” and the pre-Windows 2000 name is “MICROSOFT”. My domain controller is called “SERVER1” and all my users are in the default “USERS” container.

// Import the following namespace
using System.DirectoryServices;

        /// <summary>
        /// Reset a user's domain password, using a domain administrators account.
        /// </summary>
        /// <param name="acct">User who needs a password reset.</param>
        /// <param name="username">Administrator User Name</param>
        /// <param name="password">Administrator Password</param>
        /// <param name="newpassword">User's new password</param>
        public void resetPassword(string acct, string username, string password, string newpassword)

                // LDAP Connection String
                string path = "LDAP://SERVER1/OU=USERS,DC=MICROSOFT,DC=LOCAL";

                // Prefix to Add to User Name (e.g. MICROSOFT\Administrator)
                string Domain = "MICROSOFT\\";  //Pre-Windows 2000 Name

                // Establish LDAP Connection 
                DirectoryEntry de = new DirectoryEntry(path, Domain + username, password, AuthenticationTypes.Secure);

                // LDAP Search Filter
                DirectorySearcher ds = new DirectorySearcher(de);
                ds.Filter = "(&(objectClass=user)(|(sAMAccountName=" + acct + ")))";

                // LDAP Properties to Load

                // Execute Search
                SearchResult result = ds.FindOne();

                string dn = result.Properties["DistinguishedName"][0].ToString();

                DirectoryEntry uEntry = new DirectoryEntry("LDAP://" + dn, username, password);

                uEntry.Invoke("SetPassword", new object[] { newpassword });  //Set New Password
                uEntry.Properties["LockOutTime"].Value = 0;  //Unlock Account

            catch (Exception e)
                // Log Error

The function above does all the work, but this probably won’t work by default since IIS is normally run under a low privileged local account. In order to change somebody’s password you need to use Impersonate a Domain Administrator’s account to have this capability.

** Important note, if your admin accounts are stored with your user accounts then this code could be used to reset your admin password! This is a big NO-NO since it could effectively lock you out of the network. Consider putting your users in a different container/OU and setting the filter to only look in this one place!