Mac OS X provides the Reset Password Utility that is much useful at times when you need to access your Mac and you have lost your password.
Reset Password Utility is available with the Mac OS X installer DVD until the Mac OS X Lion.
Lion has its own recovery HD Utility which can be accessed on any Mac running OS X Lion by pressing the “CMD” + “R” keys at the startup, but this recovery hd does not have the password reset utility in the utilities as it was found in the earlier OS X DVD’s .
Password Reset Utility is hidden in Lion and can be only accessed using the terminal, all you need to do is boot your mac with Lion Recovery HD and open terminal from the Utilities and simple type ” reset password” this opens up the password utility.
