MacFixIt’s Topher Kessler says if you can’t install the latest OS X 10.8.3 update Mountain Lion users after experiencing errors with its initial installation, there are several steps you can take.
Kessler notes that while the OS X 10.8.3 update install has gone smoothly for most people, the most prominent issue so far is a small number of users where the update appears to install but then gives a message that simply states “Update Failed” with an option to restart the system. Upon doing so, the system reports it is still running OS X 10.8.2; however, subsequent attempts to update result in the App Store crashing.
[Your Editor experienced a variant of this glitch, with my first attempt at installing the 10.8.3 update om my MacBook. A (mandatory) restart after the App Store app's prompt still yielded OS 10.3.2. After a re-scan by the App Store program, Software Update indicated that the update still needed downloading. I clicked the button, but this time the progress bar advanced from start to finish in about 30 seconds, followed by reappearance of the restart prompt. The second restart attempt proved the charm, and after the upgraded system sorted itself out for about 10 minutes behind a grey screen with the Apple logo, the login screen popped up and the boot-up completed nicely. - CM]
Topher Kessler has some other suggestions for workarounds should you encounter 10.8.3 update install glitches.
You can check it out at: