Return to First Boot

I repair people’s Macs for a living. Often the task requires reinstalling the operating system, and installing updates. Before I return a computer to its owner I always remove the temporary user account I created, and reset the machine back to the Setup Assistant. By following these commands, the owner has the chance to connect to wifi, create a new user account, and sign into iCloud the next time they turn on their computer.

  1. Boot into Single-User Mode by pressing ⌘-S at startup.
  2. Once the command-line prompt appears type the following commands.
  3. mount -uw /
  4. rm -R /Library/Preferences/
  5. rm -R /Users/username/
  6. cd /var/db/dslocal/nodes/Default/users/
  7. Type ls to list the contents of the directory.
  8. Delete the active user account, by typing rm username.plist where username is the name of the active account.
  9. rm /var/db/.AppleSetupDone
  10. reboot
  11. Mac OS X will restart, and the Setup Assistant will launch automatically.
If you are preparing the Mac for a new owner, press ⌘-Q and click Shutdown. The Setup Assistant run again the next time the Mac is restarted.

For Macs running Mac OS X 10.4 Tiger an earlier, follow these steps.

  1. Boot into Single-User Mode by pressing ⌘-S at startup.
  2. Once the command-line prompt appears type the following commands.
  3. mount -uw /
  4. rm -R /Library/Preferences/
  5. rm -R /Users/username/
  6. rm /var/db/netinfo/local.db
  7. rm /var/db/n.AppleSetupDone
  8. reboot
  9. Mac OS X will restart, and the Setup Assistant will launch automatically.