Windows XP Password Complexity and Expiration Policy

In Windows XP Professional, password security, complexity, and expiration rules are managed through Group Policy under the Account Policies section. Administrators can configure these rules locally using the Local Group Policy Editor or across a domain using Active Directory Group Policy Objects (GPOs). These settings enforce administrative control over how users create passwords, how long those passwords remain valid, and how frequently they must be updated to maintain system security.

To access these settings on a standalone Windows XP Professional computer:

  1. Click Start, select Run, type gpedit.msc, and press Enter to open the Group Policy Editor (or type secpol.msc to open the Local Security Policy snap-in directly).
  2. In the console tree, navigate to: Computer Configuration > Windows Settings > Security Settings > Account Policies > Password Policy.

Within the Password Policy container, several key policies govern complexity and expiration rules.

Password Complexity Rules

The primary setting controlling password strength is Password must meet complexity requirements.

When this policy is set to Enabled, Windows XP enforces the following criteria whenever a user creates or changes a password:

  • The password cannot contain the user's account name or parts of the user's full name that exceed two consecutive characters.
  • The password must be at least six characters in length (or the value defined in the Minimum password length policy, whichever is greater).
  • The password must contain characters from at least three of the following four categories:
    • English uppercase characters (A through Z)
    • English lowercase characters (a through z)
    • Base 10 digits (0 through 9)
    • Non-alphanumeric characters (for example, !, $, #, %)

To enforce minimum size, administrators use the companion policy Minimum password length, which allows setting a requirement between 1 and 14 characters. Setting this value to 0 allows blank passwords.

Password Expiration Rules

Password expiration in Windows XP is managed through two coordinated policies:

  • Maximum password age: Determines the period of time (in days) that a password can be used before the operating system requires the user to change it. Values range from 1 to 999 days. Setting the value to 0 disables expiration entirely, meaning passwords never expire. By default, domain accounts in Windows XP typically default to 42 days, while standalone local accounts default to 0 (no expiration).
  • Minimum password age: Dictates the period of time (in days) that a password must be used before the user is permitted to change it again. This setting prevents users from repeatedly changing their password immediately to bypass the password history policy. It can be set between 1 and 998 days, but it must be less than the Maximum Password Age setting.

Supporting Policies

Two additional policies under this node support expiration and complexity workflows:

  • Enforce password history: Determines the number of unique new passwords that must be used before an old password can be reused (from 0 to 24 remembered passwords).
  • Store passwords using reversible encryption: Allows the operating system to store passwords using reversible encryption, which is equivalent to plaintext storage and should remain disabled unless required by specific authentication protocols such as CHAP.