Best wau to deal with it would be the same as a lost password as follows:
If you have XP Pro on your computer, at the log in screen type
ctrl-alt-delete
twice. In the user account type administrator, leave the password
blank and press enter. You likely didn't create a password for this
hidden account during setup and if the computer was purchased with XP
pre-installed it doesn't likely have one either,
If you have Home, boot into Safe Mode (F8 after the post test and before
Windows starts. Once Windows starts loading, you've missed it and will
have to try again). You'll have an option to log on as Administrator.
Again, the same procedure, you'll be asked to log in to get into safe
mode, type administrator, leave the password blank and press enter.
This will get you in. Then go to Control Panel, user accounts, select
the specific user and select change password. Once you've changed the
password it would be advisable to create a Password Reset Disk by
clicking "Prevent a Forgotten Password" link in the left pane.