Appendix A: Installing OS X 10.8 Mountain Lion
IN THIS APPENDIX
Preparing a Mac for OS X installation or upgrade
Installing or upgrading OS X
Transferring data from a PC
Setting up a Mac after installation
Transferring applications and data from another Mac
Installing Java
Reinstalling OS X in case of failure
You can't, of course, use OS X Mountain Lion until it's installed on your computer. If you've recently bought a brand-new Mac, it's likely that OS X Mountain Lion is already installed, although you should still check to see if there have been any updates using the Mac App Store's update facility (choose 
⇒Software Update to check).
However, you may already own a Mac with an earlier version of OS X and want to upgrade to Mountain Lion. Or you may have no operating system at all on your Mac because of a hard disk crash and thus require a fresh install.
Upgrading or installing OS X is a relatively easy process, and Apple has created a custom installer that leads you through the process step by step. But before you go about installing anything, you first need to ensure that your Mac can run OS X Mountain Lion. (The quick check: If your Mac runs OS X Lion, it'll run OS X Mountain Lion.)
OS X Mountain Lion is designed to take full advantage of the multi-core processors found in the latest generation of Intel computers. Because of this, your Mac must meet these official system requirements: ...
