Do you want to change/remove the password of another user's User Account in XP?
For this trick you no need to know their previous password.
Just Click Start->Choose Run there type
control userpasswords2 and hit enter.
Now You'll get this window representing as something like list of users.
Select any user from the list and click Reset Password
and type in a new password that you want, you don't need to know the old password.
Enjoy this trick in your Friends Pc's to make fun around with them