How can I restore a MacBook Pro to factory settings without the original disc?

Question

How can I restore a MacBook Pro to factory settings if the original disc is lost?

Answer 1

On 10.7 and 10.8, you can start up from the recovery partition, erase the disk in Disk Utility, and download and install a new version of OS X. It's free if your Mac was preinstalled with 10.8, but I don't know about other cases. If you don't erase the disk first, it will just do do an upgrade install over the current installation.

If you are on 10.6 and your Mac supports 10.8, you can buy 10.8 from App Store first. Installing it always adds the recovery partition.

The installation disks that came with Macs don't usually work with other types of Macs, but the ones that were sold separately do of course. Apple no longer sells installation disks, but you can still download torrents for them or buy them used.

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Answer 2

Before macbooks sold with Lion pre-installed, there isn't a hidden image letting you reinstall without the CD, you need the CD or USB. A retail disk (what you bought to upgrade from Leopard to Snow) will work on any Mac, so you can borrow it from a friend. An included, unprinted CD is generally tied to the type and year of mac, so only try that if it matches.

Answer 3

Reboot the computer.

Hold down command+s after the chime.

At the prompt enter the following. Hit return after each line.

mount -uw /
rm /var/db/.AppleSetupDone
shutdown -h now