With XP, if you're in a workgroup, you have the option under your profile to create a password reset disk (Start, Control Panel, User Accounts, [account name], Create a Password Reset Disk, Create Disk) using a wizard:
When the wizard starts, click Next.
Select the drive that contains the media you want to create the information on (you can use a diskette or a Zip disk), and click Next.
Type your current password, and click Next.
The password reset disk contains only one file, userkey.psw, which is an encrypted version of your password. If you change your password, the password reset disk is useless, you must repeat this procedure.
To use the password reset disk, at the logon screen, leave the password field blank and press Enter or click the right arrow. The system will display a dialog box that offers the "Click here to use your password reset disk" option.
When you select this option, a wizard starts:
Select the drive to read the password reset disk from, and click Next.
Enter a new password twice, and click Next.
Type your new password to log on. Note that the password reset disk is now useless, and you must create a new one.