About the Mac OS X v10.6.4 Update

Mac OS X v10.6.4 Update Updating your system You should back up your system before installation; you can use Time Machine. Do not interrupt the installation process once you have started to update your system. You may experience unexpected results if you have third-party system software modifications installed, or if you've modified the operating system through other means. Choose Software Update from the Apple () menu to check for the latest Apple software via the Internet, including this update. If your computer is not up-to-date, other software updates available for your computer may appear, which you should install. When Software Updates states "Your software is up to date," you can be sure that all available updates have been installed. Note that an update size may vary from computer-to-computer when installed using Software Update. Also, some updates must be installed prior to others, so you should run Software Update more than once to make sure you have all available updates. You can manually download the update installer. This is a useful option when you need to update multiple computers but only want to download the update once. These versions of the standalone installers are available from Apple Support Downloads.