Apple frequently releases downloadable software updates. The Software Update feature found under the Apple menu in Mac OS X makes it very easy to determine and get exactly what you need. Not only can OS X notify the user of available updates it can install them for you. 

However, lately since the first release of a Leopard (10.5.1) update users have experienced problems with the automatic updates. OS X expert now suggested that users should use the standalone installer instead of the automatic Software Update.

Below are the steps to perform a safer OS X update instead of using the automatic Software Update feature.

The first step is to run the Disk Permissions Repair as outline in this posting (<- click on link).

Next visit the Apple OS X Download site at www.apple.com/downloads/macosx/apple/macosx_updates/

Depending if you are current with your update, only needed the next version (e.g. 10.5.2 to 10.5.3) or have skipped an update or two (e.g. 10.5.0 to 10.5.3) and need a combo update, locate the correct download file, make sure that you don’t select the Server version if you have just the standard OS X version.

Click on the Download button to start the download:

After the download is completed the disk image with the update will be mounted. Double click on the Disk Icon to open a Finder window with the content.

In the Finder window double click on the Package Icon of the OS X Update to start the installer.

In the installer window click on the Continue button:

The next window provides some important information about the update, after reading it click on the Continue button:

Next the Software License Agreement will be presented, click on the Continue button:

A pull-down window will open for you to agree to the license agreement by clicking on the Agree button:

The next window will allow you to change the install location, don’t change it just click on the Install button to continue:

You will need to enter the admin password and click on the OK button to start the install process:

The final step is to inform you that after the install a restart is required. This is your last chance to cancel the install process by clicking on the Cancel button. However, since we want to install the update we will click on the Continue Installation button:

The process status window will open to show you what is taken place.

Finally, when the install process ended successfully this window will be displayed. Click on the Restart button to restart your Mac.

After a moment just before the Mac will restart a window may open with a message “Updating Boot Caches”. Depending on the size of the update and your Mac memory and CPU speed this window may stay for some time, you can close it by clicking on the OK button, however it will not quit the restart any earlier.

When completed the system will restart, you will here the OS X startup sound and the blue and grey startup windows will open. Sometimes the system will do another restart before the final startup. Also, please be patient as the startup can take a long time should you have installed many other programs since the last OS X update. Personally I do my updates late at night so it can run over night if required.