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Perform a Clean Install of OS X Lion on Your Mac

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Use the OS X Lion Installer
Select the Lion target disk

A list of available disks that you can install Lion on will appear. Scroll though the list and select the target disk.

You're ready to start a clean install of Lion. You have performed any necessary backups, and erased a target volume for the installation. Now it's time to start the actual installation process.

  1. Before you start the Lion installer, close all other applications that may be currently running on your Mac.

  2. The Lion installer is located at /Applications; the file is called Install Mac OS X Lion. The download process from the Mac App Store also created an Install Mac OS X Lion icon in your Dock. You can start the Lion installation process by clicking the Lion installer Dock icon, or double-clicking the Install Mac OS X Lion application in your /Applications folder.

  3. The Install Mac OS X window will open. Click the Continue button.

  4. Scroll through the terms of use, and click the Agree button.

  5. A drop-down pane will appear, asking you to agree to the terms of use. Click the Agree button.

  6. The Lion installer assumes you want to install Lion on the current startup drive. To select a different target drive, click the Show All Disks button.

  7. A list of available disks that you can install Lion on will appear. Scroll though the list and select the target disk; this should be the disk you erased in the earlier step.

  8. Once the target disk is highlighted, click the Install button.

  9. The installer needs your admin password to begin the installation process. Enter the appropriate user name and password, and then click OK.

  10. The Lion installer will copy the necessary files to the target disk. Once copying is finished, you will be asked to restart your Mac. Click the Restart button.

  11. After your Mac restarts, the installation process will continue. A progress bar will display, along with an estimate of the time it will take to complete the installation. Installation speed ranges from 10 to 30 minutes.

Note: If you have multiple displays connected to your Mac, be sure to turn all of them on before you begin the Lion installation process. The installer may display the progress bar on a display other than your usual main screen; if that display isn't on, you'll wonder what's going on.

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  5. Lion - Mac OS X 10.7
  6. OS X Lion Installer Supports The Clean Install Process

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