Windows XP allows you to create a password reset disk, just in case you forget the password and can’t login. This is only for computers that are not on a domain. Those that are on a domain may or may not work the same way.
Go to Start->Control Panel->User Accounts and click on your username. Under Related Tasks on the left pane, click Prevent a forgotten password. A wizard will show up. Click next and then insert a floppy disk into your floppy drive and choose to save the reset disk on the floppy.
Enter your current password and then click Next and Finish. The floppy will now contain your encrypted password. If you forget your password, you can just use the Password Reset Wizard to create a new one. Just make sure to create another reset disk once you changed your password. So if you forgot your password and changed it to a new one, create another reset disk by repeating the above procedure again.