Change administrator password in windows 7 & vista without knowing the existing password.

Follow these steps to change the administrator password in windows 7 and vista. To do this first you should have the access to administrator account. I mean you should log into the computer as the administrator. This will not work with other user accounts. So if you think of hacking the administrator password by log in from non-administrator account, it will not going to work. Advantage of this method is, you will not asked for the existing administrator password. 

1.Click on START button and type LUSRMGR.MSC on search bar..
2.Click on "Local Users and Groups(Local)"
3.Click on "Users"
3.Then Right Click On "Administrator" or "Guest' or your user name(ex- manoj), which you want to change password.
4."set password'.
5."proceed"
6.type password, confirm it
7.then restart your computer and see....

video guide for the above trick. I should mention that this is not a hacking thing.