This post covers most of the ways of cracking windows XP users’ password

If you have an administrator account (Not Guest)

then the XP users’ passwords can be reset using command prompt.

Go to the task-bar and click on the Start button, then click on run and in the place given on dialog box type “command”, press enter.

Now In the Command prompt type “net user”
the screen will display the list of users available on machine

suppose there are three administrator users with the name of admin1, admin2 and admin3

then the password of any user can be changed by logging into the account of any one administrator

for example if we want to change the password of admin1

then we can change it from the following command

net user admin1 password

similarly for other desired users

The general syntax is for changing password is

net user

Limitations: The above method will only work if you are logged in as the administrator user.

Source From:http://www.thehackerslibrary.com/?p=38