Installing software updates

This FAQ outlines our recommended process for installing software updates, specifically Mac® OS X Updates. It is derived from the "Software Update" chapter of our book, Troubleshooting Mac OS X, and outlines the general procedure we use for installing updates delivered via Mac OS X Software Update.

Our book provides additional advice on troubleshooting software updates, including the Software Update application itself, and recovering from failed updates.

1. Familiarize yourself with the update

Read the About this Update document which accompanies all Mac OS X Updates. These documents provide important information, including any special instructions for installing the update.

2. Decide if you need to update now

Before installing software updates, you should decide if "now" is the right time. This depends on your individual circumstances. Some examples of when you may want to postpone an update:

• Deadline looming? You might want to pass until you have time to troubleshoot any problems that might occur as a result of the update.
• Malfunctioning system? Fix the problems before updating unless the update addresses the specific problem you are experiencing, as noted in the About this Update document. Updating a malfunctioning system usually makes a bad problem worse.
• Using third-party system modifications or menu extras? You may want to wait a couple of weeks to see if their authors publish updates as these items can cause problems after Mac OS X Updates. You can also disable or uninstall such items before updating your software.
• Apple® warns about the potential for problems caused by third-party modifications in the About this Update document corresponding to most of its software updates, as seen in the following example:

If you decide to update, follow the remaining steps in this FAQ in the order specified.

3. Connect your computer to a reliable power source

• If you are using a laptop or portable computer, connect it to its charger: do not attempt to update your software while running on battery power.
• If you are using a desktop computer, we recommend you invest in an Uninterruptible Power Supply (UPS).
• While not required for performing software updates, a UPS will protect your desktop from power outages and a variety of other power-related ills. For our advice on UPS selection, see the "Protecting Against Power Problems" chapter of our book, Troubleshooting Mac OS X.

4. Check your Mac OS X startup disk

Run Steps 1-2 of the Procedure in our "Resolving Disk, Permission, and Cache Corruption" FAQ. Correct any reported disk problems before proceeding, as noted in that FAQ.

5. Backup your Mac OS X startup disk

Having a valid backup of your current Mac OS X installation is the best insurance against a failed update and provides you with a viable fallback position if either the update fails or it causes problems.

We make two backups: a bootable Duplicate and a Backup Set, using the comprehensive backup and recovery solution detailed in our "Backup and Recovery" FAQ.

At a minimum, we recommend making a bootable Duplicate of your startup disk, then testing that Duplicate to make sure it boots.

6. Disable or uninstall third-party modifications and menu extras

[Optional, Recommended] If you are using third-party system modifications, such as interface hacks or third-party menu extras, we recommend disabling or uninstalling them. As noted previously, these items are often the cause of problems after installing a Mac OS X update that completed successfully.

If you use such items, elect not to disable or uninstall them before installing an update, then encounter problems after successfully installing a Mac OS X update see our "Troubleshooting Startup and Login Items" FAQ.

7. Dedicate your Mac to performing the update

1. Quit all running applications other than System Preferences > Software Update
2. [Optional, Recommended] Disable the Screen Saver and set Sleep to Never for both computer and display in Energy Saver preferences. We personally like to watch the update installation process uninterrupted so that, if it fails, we know where it went awry.
3. Do not make changes to your Mac, such as hot-plugging or unplugging peripherals, or use other applications while a software update is installing.

8. Install the update

1. Perform any special instructions, as specified in the About this Update document, that are required before installing the update.
2. Install the update:
   1. If you have a reliable network connection, run Software Update to install the desired updates. Note that some updates are so large as to make broadband almost a requirement.
   2. Otherwise download the updates you plan to install, then install them using the instructions provided in the About this Update document.
3. Perform any special instructions, as specified in the About this Update document, that are required after installing the update.

We have always installed the "Delta" versions of Mac OS X updates via Software Update and not experienced any problems with this approach.

9. Restart your Mac and test the update

Restart your Mac, log in to the account you normally use, and test your applications to assure the update is working correctly.