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Right now, the newest iteration of OS X is 10.11, known as El Capitan. Previous versions include 10.10 (Yosemite), 10.9 (Mavericks), 10.8 (Mountain Lion), 10.7 (Lion), and 10.6 (Snow Leopard). There are multiple ways to install each version of Mac OS X on your PC; we've written guides for a few of them and listed them below. OS X Lion 10.7 has now been superseded by OS X 10.8 Mountain Lion. Lion, coming just 18 months after the release of Snow Leopard OS X 10.6, was the first OS X to bring the Mac closer to the iPhone's and iPad's iOS operating system, making full use of Trackpads and gestures to use your Mac.
If your Mac is running OS X Lion or Mountain Lion, follow these steps to upgrade to El Capitan. Download the El Capitan installer from Apple. The file size is 5.8 GB, so the download may take a while, depending on the speed of your Internet connection. Mike shows you how to upgrade your Snow Leopard, Lion, Mountain Lion, Mavericks, or Yosemite Mac to El Capitan. It’s easy and a good idea to stay updated!Dir.
Looking at the specs, it looks like your MacBook Air supports OS X El Capitan and will also support macOS Sierra when it is released.
To get OS X El Capitan, you only have to download it from the Mac App Store (it will show an error message if your Mac is not compatible). The installer will show up when the download finishes, so follow its steps. Make a backup of your files on an external drive before upgrading (the easiest way to do one is through Time Machine).
Jun 21, 2016 6:04 AM
I have a late 2009 iMac with a 3.06 GHz Intel Core 2 Duo processor. I am running OS X Lion 10.7.5 and would like to upgrade to OS X El Capitan. When I try to purchase OS X El Capitan 10.11.6 via the App Store, I receive the following msg from App Store: 'We could not complete your purchase. This version of OS X 10.11 cannot be installed on this computer.'
I have >420 GB memory available on my hard drive and El Cap 10.11.6 only requires >6 GB.
The App Store info about El Cap 10.11.6 says 'Compatibility: OS X 10.6.8 or later', so my iMac should be compatible with this OS X.
Os X Mountain Lion 10.8 Download
Do I need to first upgrade to a different OS X? Which OS X?