Before you upgrade, we recommend that you back up your Mac.You should also have your Apple ID and password handy.Note: To install or upgrade other versions of OS X, see How do I install OS X 10.9 (Mavericks)? You may have to reinstall some applications, however. Before attempting to install or upgrade Mac OS X, verify that your computer meets the minimum system requirements. If you follow these steps, the installer will replace your operating system if one is already present, but will preserve your account information and personal files.The first desktop version, Mac OS X 10.0, followed in March 2001. Releases were code named after big cats from the original release up until OS X 10.8 Mountain Lion.Beginning in 2013 with OS X 10.9 Mavericks, releases have been named after landmarks in California.The alternative way to start the install process is to boot directly from the DVD, without first mounting the installation DVD on your desktop.Use this method when you’re having problems and you’re unable to boot to your desktop.
Launched in 2001 as Mac OS X, the series is the latest in the family of Macintosh operating systems.When you’re ready to upgrade to Leopard (OS X 10.5), you will need to decide what type of installation to perform.OS X 10.5 offers three types of installation: Upgrade, Archive and Install, and Erase and Install.If you’re unable to correct the problems you’re experiencing, then you may wish to consider one of the other installation types (Archive and Install or Erase and Install), in order to end up with a correctly functioning installation of OS X 10.5 Leopard.If you’re ready to perform an upgrade installation of OS X 10.5 Leopard, then gather up the necessary items and we’ll get started.