Hey I discovered a new idea. It was actually mistakenly discoverted when I was doing Netstat on DOS.

You can change the password of any user from your account. Below is process to do this:

1. Open Run command from Start–>Run
2. Type Net user [username] *
3. DOS like window will pop up type your password there and you are done…

Note: remember that there is the star symbol after the username.. and avoid the brackets too… You will not see the input information while changing password

It works try it But do u have all the privileges of the computer. I mean not limited mode.