How to change Admin password in MAC OS X without using install disk

If you don't have an installer CD, it's still easy to reset the admin password.

1. Turn on your Mac and boot in single-user mode by pressing Command+S ( in windows key board its windows key for command).
2. Once it boots into single-user mode, you have to mount the hard disk in write mode, delete the .AppleSetupDone file under /var/db/(note the dot before the filename because it's hidden) and reboot. Prior to this, we'll check the hard disk consistency with fsck So, type this: