#OS X MOUNTAIN LION RELEASE DATE INSTALL#

During installation, your Mac may restart, or display a blank screen for a short time.

In the Updates window, locate the line that says Catalina.

In the App Store, on the left side of the window, select Updates.

In the menu bar, click the Apple icon to open the Apple menu.

#OS X MOUNTAIN LION RELEASE DATE INSTALL#

Do not close the lid or power off your Mac until installation is complete.ДЄfter you've gone through the preparation steps, you need to download and install the latest version of macOS.

During installation, your Mac may restart, or display a blank screen short time.

When this process is complete, an installer application named Install OS X El Capitan is placed in your Applications folder.

Follow the on-screen instructions to perform a compatibility check, and prepare for installation.

In the archive, double-click InstallMacOSX.pkg.

Double-click the downloaded archive, InstallMacOSX.dmg, to view its contents.

The file size is 5.8 GB, so the download may take a while, depending on the speed of your Internet connection.

Download the El Capitan installer from Apple.

If your Mac is running OS X Lion or Mountain Lion, follow these steps to upgrade to El Capitan. If your Mac is running Mavericks or newer, you can proceed to upgrade to Catalina. * If your Mac is running OS X Lion or Mountain Lion, you must upgrade to El Capitan before you can upgrade to Catalina. The following versions of OS X and macOS can be upgraded to macOS Catalina. If anything goes wrong, you can restore your Mac to its previous state. Back up your dataДЄlthough not required, we strongly recommend you back up your Mac before proceeding with an upgrade. However, you can still try to upgrade to El Capitan.

If your Mac is not on this list, you cannot upgrade to Catalina.

Os x mountain lion release date