There is a way to reset a user account password, but it must be done prior to forgetting the password. You would have needed to create a password reset disk.
Windoze Help wrote:
The Forgotten Password Wizard lets you create a password reset disk that you can use to recover your user account and personalized computer settings if you forget your password.
The steps to perform this task differ depending on whether your computer is a member of a network domain or is part of a workgroup (or is a stand-alone computer).
If the computer is not on a domain
The steps to perform this task differ depending on the type of user account you have.
If you have a computer administrator account
Open User Accounts in Control Panel.
Click your account name.
Under Related Tasks located on the left side of the window, click Prevent a forgotten password.
In the Forgotten Password Wizard, follow the instructions as they appear on the screen.
The only other thing I can think of is to try typing in the username "user" (minus ""quotes) and leave the password blank and hit login.
If you can login with that, you may, or may not, have sufficient permissions to change or create user accounts. It's worth a try though.