Information Technology Reference
In-Depth Information
Creating a Repair and Reinstall USB Stick
OS X installs a small set of tools on your hard disk that you can boot to should
things go wrong. Just hold down the
OPTION
key when you start your computer,
before you hear the chime sound and before the Apple logo appears. Then
use the Left/Right cursor keys to select the recovery option from the choices
that appear (you can release
OPTION
) and hit
RETURN
to boot.
Once the recovery system is running, you can access Disk Utility to scan the
disk for errors, restore from a Time Machine backup, and get access to a
Terminal window to carry out other repairs. You can even reinstall OS X from
scratch, although the files will be downloaded as needed, so you'll need an
Internet connection.
You can write this recovery toolkit to a USB memory stick, from which you
can boot the computer to get things back on the road should you find yourself
not even able to boot the hard disk. Apple has released a free utility that can
be used to do just this.
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Just insert the memory stick, run the program, and
follow the step-by-step instructions. You'll need to enter your login password
when prompted.
Creating a Full Reinstall USB Stick
Writing the entire installation system and files to a USB stick is perhaps the
best guarantee of being able to get your system up and running in the event
of a disaster, because no matter what happens you'll be able to create a clean
installation of OS X—without the need to install over an older version or
download the files.
Creating a full reinstall stick works by writing to the USB stick a hidden file
within the OS X installation package. Here's how it's done:
1.
Look in Applications within Finder for the Install Mac OS X Mountain
Lion entry that appeared when you purchased Mountain Lion from the
App Store. If it isn't there, you'll have to download the OS X Mountain
Lion installer again—open the Mac App Store, click the Purchases icon
at the top, and then click the Download button to the right of the OS X
Mountain Lion entry. You'll see a warning that Mountain Lion is already
installed, but just click the Continue button to download regardless. Note
that once the installer has completed downloading, it'll automatically run,
but you can quit it by clicking the entry on the application menu.
