When Apple released OS X 10.8 Mountain Lion yesterday, it quietly removed the option of purchasing it’s predecessor, 10.7 Lion. This is nothing really new; once a new version of the software is released, older versions generally are no longer sold.
For many, this shouldn’t be much of a problem; you can still go from 10.6.8 (the minimum OS for using the Mac App Store, where you purchase Mountain Lion) right to 10.8 for the same $20 that you’d pay for a 10.7-10.8 upgrade, and it installs the same way.
If your Mac is running an earlier version than 10.6.8, you’ll have to upgrade to that version first – the trick will be finding a 10.6 installer, as Apple no longer sells this online; though you may have some luck at your local Apple Store or at a reseller.
Whatever the case, if your computer is capable of running Mountain Lion, especially if you’re running 10.6.8 or later, the upgrade path is fairly straightforward.
The problem is that if your Mac is one of the few that were able to run 10.7 Lion but not 10.8 Mountain Lion (see our guide for finding out which Macs support which OS versions), Apple’s download-only distribution model leaves no way for you to update past 10.6.8 if you haven’t already.
Some users are reporting that if you have purchased Lion for another machine, you can still download it from Apple and install on other machines. Others claim that this no longer works, so your mileage may vary.
In the meantime, if you have upgraded to Lion but can’t go to Mountain Lion, we highly recommend you use Lion Recovery Assistant to make an external recovery disk, just in case something goes wrong and you can’t download Lion any more. A good backup wouldn’t hurt either, but that’s true for any system.
Hopefully, Apple will announce an option for late-adopters to upgrade to the latest version of OS X they can run.