Troubleshooting Mac OS X installation and software updates (Mac OS X v10.6 and earlier)

Read troubleshooting information and advice about installing Mac OS X and Mac OS X updates in Mac OS X v10.6 and earlier.

This article has been archived and is no longer updated by Apple.

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Before you install

Read about the software before installing, including system requirements

Read any "About", "Before You Install", or "Read Me" type document if one is available for the software you are installing. Be sure that your Mac meets the system requirements. Tip: If an update appears in Software Update on your Mac, the system requirements are met.

The Apple Support website contains information about downloadable software updates.

Check required disk space

Make sure you have enough disk space. Even small application or system updates may require a few hundred megabytes of space to complete the optimization phase of the installation. Mac OS X itself may require 3.0 GB of free space or more, depending on the version and installation options you select.

Connect portable Mac to AC power

If you are installing on a portable Mac, make sure that the computer is connected to the AC power while you are downloading and installing an update. During the update process, do not put your computer to sleep (by closing the lid, for example).

Have an administrator username and password available

You must have an administrator username and password to install software updates or upgrades.

Use Software Update for Mac OS X updates

Use Software Update to install all available updates until Software Update reports "Your software is up to date"

Software Update simplifies the process because it automatically checks Apple's servers and provides only a list of recommended updates for your Mac.

About "downgrade" installations

You should not reinstall an earlier version of the same software over a later version. See Don't install a version of Mac OS X earlier than what came with your Mac.

Verifying the installation

Check the build number

If you are unsure that the installation was completed, first check the software build number. If the build number of Mac OS X or other software has changed to reflect the new update, then all of the software has been installed.

Look in Software Update

Choose Software Update from the Apple menu. Click the Installed Software tab.  A list of installed updates appears, which can be sorted by name, date, or version.

Check logs (advanced technique)

If an alert box appears with a message that says: "There was an error while installing," check the logs for the specific issue.

  • Installer log: When started up from an installation CD-ROM disc or installing a package file from a disk image, choose Show Log from the File menu (or Window menu with Mac OS X v10.4). If the information in the log window is not helpful, select the Show More Detail option. If you are going to call Apple, save the log file or write down the last few lines.
    These are the locations and names of the log files:
    • Mac OS X v10.3 or later: "install.log" in /var/log folder
    • Mac OS X v10.2.8 or earlier: "Mac OS X Update" or "Mac OS X Log" in /Library/Receipts/ folder
  • Software Update log: This log is available from the Software Update pane of System Preferences. This log just lists which update had an issue. It does not give you detailed information about the issue.
  • Console log: Use the Console utility to check the logs used by Mac OS X, which are "console.log" and "system.log". Look for messages containing the word "Install" or messages that appeared during the time of the installation.

Troubleshooting an unsuccessful installation

As mentioned, you should first verify that the computer meets the requirements to install the software. Also, you need an administrator account's name and password if there are multiple accounts on the computer.

Note: Some installations restart the computer automatically, which you may not notice if you start an installation and then leave your computer. If you do not see the installer on your screen when you return, and the computer does not start up successfully after a few minutes, troubleshoot this as a startup issue.

Restart and try again

Restart your Mac, then try the installation again.

Use Disk Utility

If the issue persists, use Disk Utility to check your Mac OS X volume. You can verify a disk while started from it. If repairs are needed, start from your Mac OS X install disc and use Disk Utility to repair.

If installation stops during "optimization"

If the installation stops during "optimization," all of the software was installed. There is no risk of an "incomplete installation." The optimization phase of an installation only affects performance and not stability or features. You may force optimization to be repeated by reinstalling the software. If you were using the Software Update pane of System Preferences on the first attempt, you will need to download the standalone installer of the same software from Apple Downloads in order to reinstall the software.

If you cannot install from a disc

Try a different software update source or disc if possible

Software Updates for Mac OS X and Apple applications for Mac OS X are often available in different ways:

Try getting the software from a different source, or download it again.

Try a new administrator account

Creating a new administrator account and using it to install the update may lead to success. If you don't know how to do this, see the "If the issue occurs in Mac OS X or in various applications" section of this document: Mac OS X: How to troubleshoot a software issue.

If this works, log out and back in as your normal user. You may delete the new administrator user, if desired.

Disconnect devices not used during installation

If the issue persists, disconnect any other drives you may have connected to your computer and retry your installation. Other devices could potentially affect your installation. Disconnect or remove anything that did not come with your computer.

Remove non-Apple RAM

For installations from a disc, marginal-quality memory can contribute to installation issues; issues that may not otherwise be apparent in day-to-day computer tasks. If you have added third-party RAM, remove some of the RAM from your computer, but not so much that you are below the minimum required to install the software.

Erase install as a last resort

Erase installs may succeed where other installations do not. You should make sure you have a working backup of your important data before erasing the volume. Due to the extreme nature of this solution, you may wish to try all other steps first.

Important: Erasing a volume deletes all data on the targeted volume. Back up any data you wish to keep before performing this step.

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