How can I re-acquire InstallESD.dmg?

You need to create your bootable USB before you install Lion on your Mac. You would have to redownload Lion onto another Mac or partition that is running Snow Leopard. As long as you log into the App store under your name, you can redownload Lion. It won't let you download it onto a Mac already running Lion.

Sorry! 😟

Go to the AppStore > Purchases and download again.

Unfortunately, your only option at this point is to re-download Lion from the App Store. Making a copy of InstallESD.dmg must be done before running the Lion installer, which deletes itself after installation. Here's a link to clear instructions on how to save the Lion installer file and burn it to disc.

When you go to the App Store you will find that you cannot re-download because the store tells you it is already downloaded.

Don't wory use the Option key and select the 'Downloaded' button and you can download again.

But when you've installed it, it says 'Installed' not 'already downloaded'.

My mistake - however the tip should work....

That "Option" trick only works if you are installing over the developer GM edition, not over the retail edition. Sorry.

In AppStore option click on lion, it will change from "installed" to "$29.99" then do option click again and it will start downloading. Works on retail copy of Lion, that's what I did.

alansky1 wrote:

...Making a copy of InstallESD.dmg must be done before running the Lion installer, which deletes itself after installation. Here's a link to clear instructions on how to save the Lion installer file and burn it to disc.

Great link, thanks, alansky1.

Before doing same, is it possible to click the installer as it sits in the app folder, duplicate the installer and move this second copy elsewhere - say into the downloads folder - for safe keeping?

I've already copied the installer to 2 backup external HDs as part of my backup ritual (and given it its own partition on one HD). I don't plan on installing it anytime soon - but just want to have it for when I'm ready.

Mrs H

PS FYI - I got my installer free as part of the up-to-date program with my recent purchase of an iMac. I don't need to, but AppleCare told me, it was a one time only download as part of that program - so perhaps your re-download directions wouldn't work for me if I had to do it.

I don't see why you couldn't make a copy of the installer before launching it. Even if your installer is a one-time download, you should be able to copy it and save it elsewhere. No harm in trying.

Well, my Mac came with Lion pre-installed so I can't re-download it from the app store because i thinks I am buying it for the first time, but I had to use the option trick to find that out because it says "installed" so how do I get the InstallESD.dmg file if I can't re-download Lion?

So are you saying that option-clicking on OS X Lion doesn't give you the option to re-download the software? If this is the case, I think your next move is to call AppleCare. If you Mac came with Lion preinstalled, it must be brand new. Good luck!

monkey paw wrote:

That "Option" trick only works if you are installing over the developer GM edition, not over the retail edition. Sorry.

That is incorrect, it works for the retail edition.

I had the same problem on a macbook air 11" 2011

I was able to initiate a "Internet Recovery" with a 16GB (!!) usb stick inserted. The stick has to be formatted with DIsk Utility with a GUID Partition Scheme and MacOS Extended Format with Journaling on

An 8GB stick was not enough!

After the download which takes a good while, teh computer will restart and start the installer on the stick. Here you have to brutally interrupt all this. On the usb stick you'll find the image InstallESD.dmg

Have fun