To get the latest features and maintain the security, stability, compatibility, and performance of your Mac, it's important to keep your software up to date. Apple recommends that you always use the latest macOS that is compatible with your Mac.
Learn how to upgrade to macOS Big Sur, the latest version of macOS.
Install Mac Os X Mountain Lion.app Download
- Upgrading from Mac OS X 10.7 (Lion) Reinstalling Mountain Lion. Reinstalling while keeping files, applications, and settings; Reinstalling while erasing everything on your computer; Upgrading from Mac OS X 10.7 (Lion) Mac OS X 10.8 (Mountain Lion) is no longer available for purchase from the Mac App Store.
- First, make sure your USB drive is formatted for use with a Mac, then download the OS X Lion installer from the App Store and copy it to your flash drive. Finally, use your bootable flash drive to install Lion on your Mac. Make Sure Your USB Drive Is Formatted for a Mac Not all USB drives can be used with a Mac right out of the box.
- Download Mountain Lion for Mac. OS X 10.8 Mountain Lion is Apple's latest operating system for Mac. It brings OS X much closer to iOS in terms of features and syncing with iPads and iPhones. We've already given you a lowdown on the most important changes in Mountain Lion most of which are features taken from iOS.
Check compatibility
Also, OS X Mountain Lion takes up about 10 GB of space on its initial installation, so the computer where you install Mac OS X must have at least 10 GB of space in its hard drive. However, that's only the bare minimum; if you plan to install Mac OS X for day-to-day use, I recommend allocating at least 50 GB of space.
Install Mac Os X Mountain Lion.app Download Free
If a macOS installer can't be used on your Mac, the installer will let you know. For example, it might say that it's too old to be opened on this version of macOS, or that your Mac doesn't have enough free storage space for the installation.
To confirm compatibility before downloading, check the minimum requirements for macOS Catalina, Mojave, High Sierra, Sierra, El Capitan, or Yosemite. You can also find compatibility information on the product-ID page for MacBook Pro, MacBook Air, MacBook, iMac, Mac mini, or Mac Pro.
Make a backup
Before installing, it’s a good idea to back up your Mac. Time Machine makes it simple, and other backup methods are also available. Learn how to back up your Mac.
Download macOS
It takes time to download and install macOS, so make sure that you're plugged into AC power and have a reliable internet connection.
Safari uses these links to find the old installers in the App Store. After downloading from the App Store, the installer opens automatically.
- macOS Catalina 10.15 can upgrade Mojave, High Sierra, Sierra, El Capitan, Yosemite, Mavericks
- macOS Mojave 10.14 can upgrade High Sierra, Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion
- macOS High Sierra 10.13 can upgrade Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion
Safari downloads the following older installers as a disk image named InstallOS.dmg or InstallMacOSX.dmg. Open the disk image, then open the .pkg installer inside the disk image. It installs an app named Install [Version Name]. Open that app from your Applications folder to begin installing the operating system.
Install Mac Os X Mountain Lion Approach
- macOS Sierra 10.12 can upgrade El Capitan, Yosemite, Mavericks, Mountain Lion, or Lion
- OS X El Capitan 10.11 can upgrade Yosemite, Mavericks, Mountain Lion, Lion, or Snow Leopard
- OS X Yosemite 10.10can upgrade Mavericks, Mountain Lion, Lion, or Snow Leopard
Install macOS
Install Mac Os X Mountain Lion App Store
Follow the onscreen instructions in the installer. It might be easiest to begin installation in the evening so that it can complete overnight, if needed.
If the installer asks for permission to install a helper tool, enter the administrator name and password that you use to log in to your Mac, then click Add Helper.
Please allow installation to complete without putting your Mac to sleep or closing its lid. Your Mac might restart, show a progress bar, or show a blank screen several times as it installs macOS and related firmware updates.
Apple Mac Os X Mountain Lion 10.8 Install Disc
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You might also be able to use macOS Recovery to reinstall the macOS you're using now, upgrade to the latest compatible macOS, or install the macOS that came with your Mac.