1. On your Domain Controller, go to Start > Administrative Tools > Group Policy Management.
  2. Right-click Default Domain Policy and click Edit.
    GPM
  3. Computer Configuration > Policies > Windows Settings > Security Settings > Account Policies > click Password Policy.
  4. Set the following policies by double-clicking on them:
    • Enforce Password History: 4
    • Minimum Password Length: 8
    • Password must meet complexity requirements: Enabled