1. If i use the “reinstall OS X” option from disk utilities for reinstalling, which version of OS X will be installed? I have currently OS X 10.7.5 installed. So the question is: will it install OS X Lion or OS X Mavericks or OS X Yosemite ( now that it has been released )?
2. Download the Yosemite installer from the Mac App Store and make sure it’s in your main Applications folder (/Applications)—it’s called Install OS X Yosemite.app. Connect to your Mac a.

DVD DL, Mac OS X 10.10 Yosemite Full OS Install, Reinstall, Recovery and Upgrade Supported Models: iMac: Late 2007 or later, MacBook: Aluminum Late 2008, MacBook: Early 2009 or later, MacBook Pro: 13-inch - Mid 2009 or later, MacBook Pro: 15-inch - Mid/Late 2007 or later, MacBook Pro: 17-inch - Late 2007 or later, MacBook Air: Late 2008 or later, Mac Mini: Early 2009 or later, Mac Pro: Early. Re-installing OS X Yosimite i recently Sold my Macbook. I un installed the OS X as i have in the past, but when i try and connect to the Apple Store it keeps saying 'This item is temporarily Unavailable, Try again Later'. Oct 10, 2014 Near the center of the window, select the Format drop-down list and select “Mac OS X Extended (Journaled)” as the type. Click Erase (this will erase your main drive!) and allow some time for the drive to format. When it’s finished, close out Disk Utility and select “ReInstall OS X” from the menu. It will ask for your Mac App Store password to redownload OS X Yosemite.

On this page:

• Reinstalling Yosemite on a computer alreadyrunning it

Upgrading from previous versions to OS X 10.10 (Yosemite)

OS X 10.10 (Yosemite) is no longer available for purchase from theMac App Store. If you have a previous version of the operating system,and your computer meets the system requirementsfor OS X 10.11 (El Capitan), you can upgrade directly to thatversion instead; see ARCHIVED: Install or upgrade OS X 10.11 (El Capitan)

Reinstalling Yosemite on a computer already running it

Reinstalling while keeping files, applications, and settings

1. Restart your computer, and immediately hold down command-r until the gray Apple logo appears.
2. If prompted, select your main language and then click the arrow.
3. Click Reinstall OS X, and then Continue. Follow the instructions on the screen, and then choose your hard disk. Click Install, and enter your Apple ID information if prompted.
4. When the installation is complete, select App Store... from the Apple menu, and install any available updates.

Reinstalling while erasing everything on your computer

1. Restart your computer, and immediately hold down command-r until the gray Apple logo appears.

2. If you see a screen asking you to select your main language,choose it, and then click the arrow.
3. Click Disk Utility, and then Continue.
4. In Disk Utility:
   1. Click your hard disk in the left column, and thenclick the Erase tab.
   2. Next to 'Format:', make sure Mac OS Extended (Journaled)is selected. In the 'Name:' field, give your disk a name.
   3. If you would like to securely erase your data, click SecurityOptions..., adjust the slider accordingly, and clickOK.
   4. When you're ready, click Erase..., and thenErase again to erase your disk.
   5. Once it's completed, quit Disk Utility.
5. Click Reinstall OS X, and then Continue:
   1. Follow the instructions on the screen, and then choose your harddisk.
   2. Click Install. If prompted, enter your Apple IDinformation.
   3. Once the installation is complete, you'll beasked to enter basic information, and have the option to transfer datafrom another computer or backup.
6. From the Apple menu, select App Store, and then installany available updates.

Start up from macOS Recovery

Reinstall Os X Yosemite App Store Temporarily Unavailable

Determine whether you're using a Mac with Apple silicon, then follow the appropriate steps:

Apple silicon

Turn on your Mac and continue to press and hold the power button until you see the startup options window. Click the gear icon labeled Options, then click Continue.

Intel processor

Make sure that your Mac has a connection to the internet. Then turn on your Mac and immediately press and hold Command (⌘)-R until you see an Apple logo or other image.

Reinstall Os X Yosemite This Item Is Temporarily Unavailable

If you're asked to select a user you know the password for, select the user, click Next, then enter their administrator password.

Reinstall macOS

Select Reinstall macOS from the utilities window in macOS Recovery, then click Continue and follow the onscreen instructions.

Follow these guidelines during installation:

• If the installer asks to unlock your disk, enter the password you use to log in to your Mac.
• If the installer doesn't see your disk, or it says that it can't install on your computer or volume, you might need to erase your disk first.
• If the installer offers you the choice between installing on Macintosh HD or Macintosh HD - Data, choose Macintosh HD.
• Allow installation to complete without putting your Mac to sleep or closing its lid. Your Mac might restart and show a progress bar several times, and the screen might be empty for minutes at a time.

After installation is complete, your Mac might restart to a setup assistant. If you're selling, trading in, or giving away your Mac, press Command-Q to quit the assistant without completing setup. Then click Shut Down. When the new owner starts up the Mac, they can use their own information to complete setup.

Other macOS installation options

When you install macOS from Recovery, you get the current version of the most recently installed macOS, with some exceptions:

• On an Intel-based Mac: If you use Shift-Option-Command-R during startup, you're offered the macOS that came with your Mac, or the closest version still available. If you use Option-Command-R during startup, in most cases you're offered the latest macOS that is compatible with your Mac. Otherwise you're offered the macOS that came with your Mac, or the closest version still available.
• If the Mac logic board was just replaced, you may be offered only the latest macOS that is compatible with your Mac. If you just erased your entire startup disk, you may be offered only the macOS that came with your Mac, or the closest version still available.

You can also use these methods to install macOS, if the macOS is compatible with your Mac:

• Use the App Store to download and install the latest macOS.
• Use the App Store or a web browser to download and install an earlier macOS.
• Use a USB flash drive or other secondary volume to create a bootable installer.