How to reset a forgotten Mac password

There are two main ways: With an OS-X installation disk and without one:

With an OS-X installation disk

Use these instructions: http://support.apple.com/kb/ht1274

Without a disk

OS-X 10.5 (Leopard) & 10.6 (Snow Leopard)

1. Power on or restart your Mac.
2. At the chime (or grey screen if your chime is turned off), hold down Command+S on your keyboard to enter single-user mode.
3. This step is optional, but it’s a good idea because it checks the consistency of the hard disk before moving on. At the prompt, type fsck -fy and press Enter/Return. Wait for the checks to complete before going to the next step.
4. Type mount -uw / and press Enter.
5. Type launchctl load /System/Library/LaunchDaemons/com.apple.DirectoryServices.plist and press Enter.
6. Type ls /Users and press Enter. This lists all of the usernames on the computer – helpful if you don’t know or remember what these are.
7. Type dscl . -passwd /Users/<username> <password> replacing “<username>” with one of the users displayed in the previous step and replace “<password>” with a new password of your choice. Press Enter.
8. Type reboot and press Enter.

OS-X 10.4 (Tiger)

• Verified by Marco (2011-02-01)

1. Power on or restart your Mac.
2. At the chime (or grey screen if your chime is turned off), hold down Command+S on your keyboard to enter single-user mode.
3. Type sh /etc/rc and press Enter/Return.
4. Type passwd <username> and replace “<username>” with the short name of the user account for which you’d like to reset the password.
5. Type your desired password when prompted and press Enter. It won’t show itself on the screen, so be careful what you type. You will have to enter it again to confirm.
6. Type reboot and press Enter.