How do I install or upgrade Mac OS X?

Note: This document includes instructions for installing Mac OS X only. The instructions for also installing Mac OS 9 (i.e., the Classic Environment) vary depending on your computer and the kind of discs you have. On older computers, you can install OS 9 from a regular OS 9 installation disc, but on newer ones, you must use the "Software Restore" or "Additional Software" disc that came with your computer. Apple has more detailed information in its support library. You will also find more information in your computer's built-in Help files.

Before attempting to install or upgrade Mac OS X, verify that your computer meets the minimum system requirements; see For Mac OS X 10.5, what are the system requirements? Then continue your installation or upgrade:

1. Insert the install disc (or the first install disc if you have more than one) into your disc drive. Restart your computer, and hold down the  c  on your keyboard. This causes your computer to start up from the install disc rather than your hard drive. When you see the Happy Mac icon or the gray Apple insignia, you may release the  c .
   
   
2. The Mac OS X installer should open automatically. Follow the on-screen prompts to read and accept the license agreement and begin the installation. When prompted to choose a destination disk, select your preferred location.

   Note: Certain Macintosh models, including the beige Power Macintosh G3 and the rev. A, B, and C G3 iMacs, require that Mac OS X be installed within the first 8GB of the computer's hard drive. If your computer is one of the models listed above, and the hard drive is larger than 8GB, you must create an 8GB partition that completely contains the Mac OS X installation; see In Mac OS or Mac OS X, how do I partition my hard drive?

   If you are upgrading to OS X 10.2 or higher, you can click Options... and select from the following options:

   • Upgrade Mac OS X: This option simply upgrades your current operating system to the new version, preserving all your files and settings.
     
     
   • Archive and Install: This option creates an archive of your current System files and installs a new copy of Mac OS X. You also can select Preserve Users and Network Settings, which imports all user accounts and network settings into the new system.
     
     
   • Erase and Install: This option completely erases the destination disk and then installs a new copy of Mac OS X. If you select this option, UITS recommends that from the pull-down menu next to "Format disk as:", you select Mac OS Extended or Mac OS Extended (Journaled).

   If you are installing Mac OS X for the first time, and not upgrading, your options are to simply Install Mac OS X or Erase and Install.

3. When the Mac OS X installation finishes with the disc, click Restart. Your computer will restart, and if additional discs are required to complete the install, the system will ask you to insert them. After the install completes, a configuration program will begin automatically if you are installing for the first time or if you are archiving and installing without preserving users and network settings. You will need to supply basic setup information for your computer, including owner, network, Mail, time zone, .Mac, and Apple ID settings.
   
   
4. Install any additional software you may have and update your system software to ensure that you have the most recent operating system components. See For Mac OS or Mac OS X, how do I obtain and install system software updates?

Also see:

• In Mac OS X, what software can I use to read Usenet newsgroups?
• What is iTunes and what does it do?
• At IU, how do I configure Mac OS X Mail to read my mail through IMAP?
• How do I configure Mac OS X Mail to read my mail through POP?
• In Mac OS X, how do I quit an application that isn't responding?
• For Mac OS X, what are some useful utilities for troubleshooting and optimizing performance?
• In Mac OS X, what is the Terminal, and how do I access it?