Such changes are only made in virtual memory and they disappear after computer reboot. Have you lost your password? Kon-Boot can help! Our software works by virtually modifying the EFI bios and then modifying parts of the OSX kernel. Kon-Boot will either allow you to login into selected account without knowing the password (bypass mode) or it will create new 'root' account for you (new-account mode) from which you will be able to change other users passwords as needed. What is Kon-Boot for Macs? Kon-Boot for Apple Mac OSX systems allows the user to login into the system without knowing the previous passwords and user names.
General notes PLEASE KEEP YOUR ANTIVIRUS DISABLED WHILE EXTRACTING / BURNING / INSTALLING KON-BOOT