Currently Being ModeratedAug 27, 2011 9:39 AM (in response to gordon#)
Are you sure you actually downloaded and installed it the first time?
If the App Store is showing OS X Lion as Installed and you want to reinstall it you will need to re-download it unless you saved the InstallESD.dmg file the first time. But, before you do this, I would recommend you update SL to 10.6.8. I 'think' that's a requirement for downloading and installing Lion.
Here are steps to re-download and burn the InstallESD.dmg file (optional)....
- Use the machine OS X Lion is installed on.
- Open App Store. Sign in.
- Press and hold your OPTION key; then click on Purchases at the top of the App Store screen.
- Under your purchase, look to the right of 'OS X Lion'. If Step 3 worked, the button on the right should say Install and let you click it.
- Click Install. Let the download finish.
- When you see the window open for installing the download, open FINDER, navigate to Applications and you should see the OS X Lion Installation App.
- Right click on the OS X Lion Installation App and select Show Package Contents.
- Navigate to the SharedSupport folder. You should see a filename of InstallESD.dmg.
- Copy the InstallESD.dmg to your desktop
- Close the window that's waiting for you to install OS X Lion. It's not needed anymore.
Burn the InstallESD.dmg to a bootable DVD.
- Launch Disk Utility and click the Burn button
- Select the InstallESD.dmg file from your desktop as the image to burn. Insert a blank DVD and wait for the the image to be burned.
Burn the InstallESD.dmg to a bootable USB thumb drive.
- Open Disk Utility and drag the InstallESD.dmg file to the left side pane. Go to the Partition tab ad select 1 Partition from the drop down menu. Choose Mac OS Extended (Journaled) on the left. Click the Options button under the partition table and choose GUID Partition Table. You will need this to make the drive bootable on a Mac. Hit the Apply button when ready to format the drive (it will erase everything on the drive).
- Click on the Restore tab and drag the InstallESD.dmg file to the Source. Drag the USB partition to the Destination. Hit the Restore button and it will create the bootable USB drive with the OS X Lion installer.