How to Install Mac OS X Mountain Lion Video
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Video:How to Install Mac OS X Mountain Lion

with Nick Richards

Upgrading your Mac to OS X Mountain Lion is a lot easier than you think. This video from will show you the quickest way to install OS X Mountain Lion.See Transcript

Transcript:How to Install Mac OS X Mountain Lion

Hi, I'm Nick, and today for, I'm going to show you how to install Mountain Lion on your Mac.

Make Sure Your Mac is Compatible

Mountain Lion is Apple's latest Operating System and can be purchased from the official App Store. If you want to upgrade, the first thing you'll need to do is ensure that your current computer can handle it! You'll need at least 8GB of hard drive space and 2 GB of RAM in order to install Mountain Lion. You'll also need to ensure your Mac is compatible - if you have a model released earlier than 2007, it's unlikely you'll make the cut!

Downloading Mountain Lion

To download Mountain Lion, head to the App Store and find the official Mountain Lion app. You'll need to purchase the update using your Apple ID, so click the 'Buy App' button and then enter your details in the window that appears. Mountain Lion will start downloading immediately.

Backing Up Mountain Lion

When the download is complete, the installer should open automatically, but the file can also be found in the Applications folder. Before you do anything else, it's a good idea to make a copy of the Mountain Lion file. This will save you downloading it again, in case you need it. Once purchased, you can also install Mountain Lion on any Mac computer that uses the same Apple ID, so if you have more than one Mac, you'll only have to buy Mountain Lion once!

It's also a sensible idea to perform a back up of your hard disk, just in case something goes wrong.

Performing an Upgrade Install

To perform an upgrade install of Mountain Lion, simply open the app and click the 'Continue' button. Read through the licence agreement carefully and then, if you're happy, click Agree. From here, you'll be able to choose which disk you wish to install Mountain Lion on to. You'll want to pick your home drive, usually labelled Macintosh HD. Finally, enter your administrator password to start the download.

Performing a Clean Install of OS X Mountain Lion

Performing a clean install of Mountain Lion is a bit more complicated. Clean installs ensure that no errors or bugs are carried over when performing the install, but requires you to entirely delete your hard disk and start again from scratch. To do this, you'll need to copy the Mountain Lion app onto either a DVD or an external drive.

Find the Mountain Lion installer and right click with your mouse cursor. From here, select 'Show Package Contents' and then 'Contents'. Next, head into the 'Shared Support' folder. The file you'll need is titled, 'InstallESD.dmg.' From here, open Disk Utility. You can burn the .dmg file onto a double-sided DVD by clicking 'Burn', or you can click 'Open' if you plan to use a hard drive. Open the 'Restore' menu and make sure that the Mac OSX Install ESD is in the Source and your external drive is in the Destination and click 'Restore' and then 'Erase'.

Now, restart your computer and hold the 'alt' key to be able to select your bootable media. From here, click 'Disk Utility'. Make sure your main hard disk is selected and then open the 'Erase' tab. Make sure that the format is 'Mac OS Extended (Journaled)' and type in the name for your disk. Now click 'Erase'. Now you can head back to the home page and choose the Reinstall Mountain Lion option. This should take about an hour or so, but when it's finished, you'll have a completely clean copy of Mountain Lion on your computer. Don't forget to restore all of your data as soon as you can!

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