A few words of thanks would be greatly appreciated.

Install or reinstall Mac OS 10.5

Before beginning to install or reinstall MacOS 10.5, determine if it is really necessary to do so. Prior to installing MacOS, it is important to check for updates of the internal program - Firmware for PowerPC Macs or EFI or SMC for Intel-based MACs.The installation can be completed using the CDs or DVDs shipped with the MAC. Before starting, take a backup of important data including Mail, Address Book, Calendar, Safari, Firefox, etc, so that it can be copied back after the installation of the operating system is completed. Follow the instructions on the installation CDs/DVDs to install or reinstall MacOS 10.5.


First and foremost, you must verify that the Mac does not require an update of its internal program.
(This is also known as firmware for PowerPC Macs, and EFI for Mac Intel)

Verify that the Mac is not affected by an update of firmware for the DVD player (the Superdrive). This is often the case with the PowerMac G5 2004, PowerMac G4 Digital Audio, PowerMac G4 QuickSilver (eMac USB2.0) and iMac G4 Flat Panel 15 ".

The installation CD or DVD you use must be suitable for the type of Mac you are using and it must be an authentic licensed copy.


  • The destination hard drive must be in the Mac OS Extended Journaled format and not in the UFS format. If your Mac OS is already in the UFS format, it will require a special procedure in order to recover the files.
    • This procedure is described HERE
  • MS DOS (FAT 16 or FAT 32)and the NTFS format, are not valid either for the installation of Mac OS 10. These Windows formats. If you are installing MAC OS on a new external drive, start by formatting the new hard disk to Mac OS Extended (Journaled) format as almost all hard drives these days are pre-formatted in MS DOS or NTFS.
  • To reformat a disk, you should use the Disk Utility. For creating partitions, use the Apple partition scheme for PowerPC-based Macs and the GUID partition scheme on Intel-beased Macs.
  • If you want to perform an "Erase and Install" installation, be sure to back up and data you want to keep.

What should your backup consist of?

Most of the backup procedures can be done rapidily using the protocol established by Apple and explained on this page

But sometimes it may be interesting to know how to recover these items manually.

Here are the paths to backup and reinstall your files manually:


  • The folder that contains all the mail is called "Mail", it is at this location:
    • Hard Disk/Users/username/Library/Mail
  • What you need to do is copy this folder from the old account and transfer it to its original location (same path) in the new account.
  • The system will ask if you want to replace an existing (albeit blank) folder.
  • Select Yes.
  • The preference file for Mail is here:
  • Hard Disk/Users/username/Library/Preferences/com.apple.mail.plist
  • Repeat the steps above for this folder.
    • If you use Thunderbird, the folder that contains your messages is located here:
    • Hard Disk /Users/username/Library/Thunderbird

Address Book

  • The "AdressBook" file is located here:
    • Hard Disk/Users/username/Library/Application Support/AdressBook

Calendar / Events

  • The iCal file is located here:
    • Hard Disk/Users/username/Library/Calendars

Safari (bookmarks)

  • The bookmarks in Safari are here:
    • Hard Disk/Users/username/Library/Safari/ Bookmarks.plist

FireFox (bookmarks)

  • This file is located here:
    • Hard Disk/Users/username/ Library/Application Support/Firefox/Profiles/bookmarks.html

Keychain Access

  • The Keychains folder is located here:
    • Hard Disk/Users/Username/Library/Keychains

Sticky notes/Reminders

  • The file that contains all your notes is called StickiesDatabase, it is located here:
    • Hard Disk/Users/username/Library/StickiesDatabase


  • The "iTunes Music" folder, which contains all your music albums and podcasts, is where you decided to place it in your iTunes preferences (iTunes/ Preferences/Advanced/ "iTunes Folder Location")

The folder "iTunes", is located in your "Music" folder and it contains the: Album Artwork, iTunes Library, iTunes Library Extras.itdb, Genius.itdb iTunes Library, iTunes Music Libary.xml


The iPhoto Library is located in your Pictures folder.

Data-Microsoft Entourage

All of the folders related to "Microsoft User Data" are located directly in your Documents folder.


iLife application suite -When installing Leopard on an earlier version of Mac OS (Tiger, Panther, Jaguar, ...)
  • If you are installing Leopard on a Mac running an earlier version of OS, the iLife applications are not included with the installation DVD. If you are performing an "Erase and install", you will need to back your these applications up.
  • You can also prepare the installation packages for applications involved by extracting them from installation CD of the original Mac using Pacifist.

The applications available in iLife are:
  • iMovie
  • iDVD
  • GarageBand
  • iWeb
  • iPhoto

Note: The old versions of iLife may cause problems in Leopard and in this case you will need to purchase the latest iLife suite.

Installation: prerequisites

Software, updates and important documents

Be sure to keep a backup of all purchased software and any updates. You should also go through your hard drive and back up any files you don't want to lose.

Settings and documents

You should make a note of:
  • The QuickTime Pro serial key (in QuickTime preferences).
  • Your internet connection settings.
  • The email account settings.


Note that depending on the type of DVD (Universal DVD) support, there may be small differences.

Insert the CD or DVD

  • Restart the Mac while keeping the C key pressed until you see the installation window. Alternatively, double-click on the "Install Mac OS X" icon, then click the "Restart" button.
  • Initially, the Mac checks the status of the installation DVD, but you can click on "Ignore" to skip this step.

1st Step

Choose the installation language and the country where you live.

2nd Step- the Welcome Window

Click "Continue".

Note: At this stage, it is possible to click on "View more info" for system requirements and have some information before starting the installation.

3rd Step- The License Window

Click on "Accept".

Step 4 - Select the installation path

Select the volume where you want to install Leopard and click on "Continue".
  • If the desired disk is crossed by a yellow warning sign instead of the green arrow, it may be that Mac OS is already installed and you will need to click on the Options button to choose the installation type.(Recommended).
  • If the destination disk crossed with a red no-entry panel, it indicates that the disk will not support Mac OS 10 and it will probably be needed to be formatted, as mentioned above.

Click on "Options" to select the type of installation.

Choose between the Archive and Install or the Erase and Install modes.
  • It is not recommended to choose "Upgrade Mac OS X" as it is known to have caused problems for users in the past. Choosing "Archive and Install" and checking "Preserve Users and Network Settings" achieves nearly identical results, without any of the potential problems. This will keep each User's own settings, files and contact safe.
  • Archive and Install feature

The Erase and Install feature completely erases to contents of the disk and starts fresh. It is therefore important to be careful using this feature as erased files cannot be retrieved.

5th Stage - Install

By choosing to customize your installation, rather than opting for Standard, you can save disk space by installing only what you want. You can uncheck any unnecessary:
  • Languages
  • Drivers
  • Foonts

When you are happy, click Done. The installation will begin as soon as you click Install.

Upon restarting the Mac

After performing an Archive and Install, you will need to download any updates manually. Do this by selecting Software Updates in the Apple menu.

After performing and Erase and Install, you will see the set up wizard that can help you update your machine.

Once you have updated the system, you can use the Disk Utility to repair the disk permissions.


All that remains now is to configure your machine:
  • Select your keyboard type
  • Do you already own a Mac?
    • You can choose to transfer your data from another Mac. If you decide to transfer files, you must use a FireWire cable to connect the two Macs.
  • Enter your Apple ID:
    • If you already have one you can use it, but this feature is optional. Click "Continue" if you do not want to register an account.
  • Registration
  • Computer's name
    • Choose your name wisely and don't use special characters in your name.
    • You must also set a password for your administrator account. You cannot run your Mac without a password.
  • Select a picture for the account
  • Internet connection Wizard.
    • This will help you to set up your internet connection
  • Subscribing to MobileMe (optional; paid service)

Time Machine

Be careful when you first start up Mac OS 10.5 with an external drive connected. Mac OS will prompt you, asking if Time Machine can use this external drive as a backup disk. If you agree, this external drive will be erased and formatted.


Original FAQ on CCM

A few words of thanks would be greatly appreciated.

Ask a question
CCM is a leading international tech website. Our content is written in collaboration with IT experts, under the direction of Jeff Pillou, founder of CCM.net. CCM reaches more than 50 million unique visitors per month and is available in 11 languages.


This document, titled « Install or reinstall Mac OS 10.5 », is available under the Creative Commons license. Any copy, reuse, or modification of the content should be sufficiently credited to CCM (ccm.net).