By default, Windows XP passwords will expire after 42 days. Windows will start warning you of this expiration 2 weeks prior.

XP Pro & Home

Expand the Windows settings under Computer Configuration. Expand Security Settings, expand Account Polices, click Password Policy. Double-click “Maximum password age” and set to 0 (zero).

To prevent this from happening, go to==>Control Panel, Administrative Tools, Computer Management. Expand Local Users and Groups. Click on Users. Double-click the user. Now on the General tab, click the “Password never expires” check box. Click OK.

XP Pro

If you’re using Windows XP Professional, you can make it a global setting (all users). Go to Start then Run, and enter gpedit.msc.