If you do not want your passwords to expire then follow the steps:
- Go to Start > Run and in the Open: box type control userpasswords2
- Select the Advanced tab in the User Accounts window
- Press the Advanced button below the Advanced user management header
- Select Users in the Local Users and Groups
- In the right pane, right-click the user name for which you want to change the setting, and select Properties
- On the General tab, check Password never expires
- Click Apply and OK (all the way out)