There's a simple way to reset the password. It involves deleting a system file, bringing the OS back to a no admin password state. I tried this once myself and it did work. The problem is that the readme file I saved with the instructions wound up corrupted in a data backup. There is a way to do this without any third party applications or elaborate hacks.
Possible solutions:
(1) A step-by-step straight from the Death Star:
http://support.microsoft.com/kb/321305Method 2: Log on as an admin'tor to reset the password
Windows XP Home Edition or Windows XP Professional
1. Log on as an admin'tor.
a. Restart the computer.
b. Press CTRL+ALT+DELETE two times, and then type the name of the admin'tor user account.
c. In the Password box, type the admin'tor password, and then click OK.
Note If the admin'tor password is set to a blank password, do not type a password before you click OK.
2. Reset the password.
a. Click Start, click Run, type control userpasswords2, and then click OK.
b. Click the name of the user account that you want to reset the password for, and then click Reset Password.
c. Type a new password in the New password box, and then type the password again in the Confirm new password box, and then click OK.
d. Restart the computer, and then try to log on to Windows XP again.
(2)
http://johnmonte.wordpress.com/2008/03/06/...password-reset/For the future, here's how to create a PW reset disk so if you forget it again, you have a tool to recover it:
http://pcsupport.about.com/od/tipstricks/h...assworddisk.htm