You can change ADMINISTRATOR PASSWORD IN WINDOWS 7 AND WINDOWS VISTA.BY FOLLOWING THESE EASY STEPS.
1.Click on START button and type LUSRMGR.MSC on search bar and once found click on it.
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- Harry), which you want to change password.
6.type password, confirm it
7.then restart your computer and enjoy.
Disclaimer: The above steps shared for users who lost their administrator password. Please do not use to reset other user computer passwords. Please try the steps at your own risk.