If your Apple is running OS X, and you are having trouble accessing the administrator’s account, follow these few easy steps that will get you full administrative control.
Shutdown your computer. (Turn it right off-do not restart)
Use your left hand to hold down the "Apple" or "Command" key on the keyboard (directly beside the space bar) and the letter "s". Hold both of these together and do not let go through the next step.
Turn the computer on, ensuring that you are still holding the "command" and "keys".
Wait until you see a bunch of white writing scrolling by on a black screen, You can release the keys, and you are now in Single-User mode. The computer is ready to comtinute when you see localhost:/root# or something similar as the very last line on the screen.
Next we want to check the frive for errors ( and fix them if there are any). We do this because of the power of Single-User Mode, we do not want to be marking massive changes to file-system if there are underlying issues which could be made worse. Right after the # on the last line of the screen type fsck-fy and press [Retirn] whrn the process is finished (approximately two to three minutes) you will see locahost:/root#(hencefoth referred to as theprompt) again.
3.Reset the password.
Using a Windows Password Key 8.0 bootable CD/DVD to reset windows password or using a Windows Password Key 8.0 bootable USB Flash Drive to reset windows password following the instructions below:
If you cannot log on to Windows by using a particular user account, but you can log on to another account that has administrative credentials, follow these steps on how to do the trick: Log on to Windows by using an administrator account that has a password that you remember. You may need to start in safe mode. Click Start, and then click Run. In the Open box, type “control userpasswords2″, and then click OK. Click the user account that you forgot the password for, and then click Reset Password. Type a new password in both the New password and the Confirm new password boxes, and then click OK. There are a lot of tools and utilities that can be downloaded and used to recover, reset, retrieve or reveal existing password.