Apple Inc. has released Security Update 2008-006 for users of its Mac OS X version 10.4 operating system (code-named Tiger). This complements the operating system update for version 10.5 issued yesterday and is recommended to all users of Mac OS X version 10.4.

Tiger is the previous version of the operating system and can be found on older Macintoshes. Although it is no longer being actively developed by Apple, they continue to issue regular security updates to improve the security of your computer.

If you are unsure which version of Mac OS X you are using, go to the Apple menu at the top-left of the screen and choose ‘About This Mac’. A new window will open, the version number is given about half-way down the window, you are interested in the first two numbers. If the version number begins 10.4. then you need to install this security update. Please note, if you are running versions 10.1, 10.2 or 10.3 you should strongly consider updating your operating system immediately as these products are no longer supported by Apple and contain unaddressed security flaws.

Security Update 2008-006 fixes weaknesses in a large number of components inside Mac OS X 10.4. Many of these bugs could allow attackers to compromise the security of your computer and steal confidential data. You should install this update as soon as possible.

The best way to update your machine is to choose Software Update which can be found by clicking on System Preferences in the Dock, then choosing Software Update; or through the Apple menu at the top-left of the screen. Software Update will check for the latest updates applicable to your machine. If your computer is not up-to-date, other software updates available for your computer may appear which you should install. An update’s 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.

If you want to download the update manually, you can find the Mac OS X update page by following the link at the end of this article. Please make sure you are downloading the correct version for your computer!

Apple has released different versions for different generations of Macintosh and different versions of Mac OS X 10.4. Older Macs used so-called PowerPC microprocessors and include the Powerbook and iBook laptops, the PowerMac desktop machines and the G3, G4 and G5 iMacs. If you have one of these machines you should download the PPC update.

If you have a more recent Macintosh it will use a microprocessor from Intel. These machines include the MacBook or MacBook Pro laptops, MacPro desktop computers and Intel iMacs. if you have one of these machines then you should download the Intel download.

A few of you may use the more expensive Server version of Mac OS X 10.4 – this is used mainly on computers serving web pages or holding large amounts of data. If you use Mac OS X 10.4 Server, then you should download the Security Update 2008-006 Server file appropriate to your computer’s microprocessor.

These are very large files, ranging between 68 and 157Mb and will take a considerable time to download. Your machine will need to be restarted after the update has been installed, so please save any data before beginning the update process. When your machine has completed the installation, it will reboot twice – this is quite normal. It will also take longer than normal to restart the first time after completing the update – again this is normal.