How to Install Mac OS X 10.7 Lion Without Snow Leopard

By Sidharth | Apple

So you’re all excited to upgrade to the latest Mac OS X 10.7 Lion only to know that installing Lion is possible only when you have Snow Leopard pre-installed? It’s true that Mac App Store only works on 10.6.6 or above version of Mac OS. However, that doesn’t mean you can’t install the Lion without Snow Leopard. You can. I have.

To be able to install Mac OS X 10.7 Lion on your machine, all you need is the Lion installation file which you can grab from the Mac App Store. So, if you know someone who has already purchased Lion, ask him to get the file for you. Read this.

Installing Mac OS X 10.7 Lion on my iMac.


Before we dig into how to install Mac OS X Lion on your machine, make sure you follow these steps:

  • Backup. Needless to say, this is important. You can use Time Machine, or clone the backup and transfer the data to external Hard Disk.
  • Have a copy of Mac OS X Lion. When you are downloading Mac OS X 10.7 Lion off the Mac App Store, make sure to copy the installer file and save it where it is easy to find — remember that one can always have multiple copies of Mac OS X Lion installed.
  • Lastly, although optional, replace your keyboard, mouse with new batteries, or recharge the batteries. I have been put in a stage where my Mouse batteries where at 8% during installation of Lion and the frequent disconnection left me with nothing but frustration. Luckily, I had an extra USB mouse going along for the ride.

Assuming that you have already followed the above steps, here’s what you need to do for installing Mac OS X Lion without Snow Leopard:

— Boot into the Operating System — Mac OS X Tiger, Leopard, Snow Leopard, whatever. Now, open Finder.

— You’ll find a folder named “System.” Click on this folder where you’ll have to navigate to the “Library” folder as shown:

— Clicking on the Library folder will result in many other sub-folders. Reach out for the folder named “CoreServices.”

— Search for the file “Systemversion.plist” inside the CoreServices folder. Click on it and open using any text-editor. I’ve used Text Wrangler to open this file. And while you’re at it, why don’t you backup this file, just in case if you’ve done it wrong!

— Now that you have opened the file, change the number to 10.6.6 or above as shown. For instance, you can replace 10.4 (for Mac OS X Tiger) to 10.8 — which is the latest Snow Leopard update. I’ve changed from Mac 10.6.4 to 10.7 version. Once you have changed the number, save the file and exit.

— Restart your Mac.

— You can now install and upgrade to the new Mac OS X Lion file by launching the installesd.dmg file!

If you have any questions, feel free to let me know.

About the Author

Hi, I am Sidharth. Full-time blogger. Editor of Blogote. And a self-proclaimed geek!

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(16) comments

Didi August 15, 2011

Hi! I have a mac book running on os 10.4.11 and i want to upgrade to lion. I was able to change and save the numbers in the plist file.however, when i restarted my mac book, and tried to run the lion app installer on my external drive, it says it is not authorized to run os 7 on my mac book. what should i do? please advice. thanks!

    Sidharth September 13, 2011

    I have no experience with 10.4, but I think this has to do with access privileges? Have you found any solution?

diego August 1, 2011

i did all the process but once i clicked on the lion dmg icon it says”that the application Install Mac OSX Lion quit unexpectedly” try to relaunch but it keeps doing it all over again

    Sidharth August 7, 2011

    Strange. I’ll see if I can figure out the problem. Have you found the solution yet?

      Bret September 13, 2011

      I also am having this problem. Sidharth, did you ever find a solution tho this?

      Please let me know. I really wanna finish this install.

        Sidharth September 13, 2011

        Bret, this is how I upgraded to Mac OS X Lion. I can vouch for this method.

        May I know the version of your Mac OS?

        Edit: The reply button disappears after a certain level, so I’m updating this comment.

        It gives me the option to install it now (since I changed it from 10.5.8 to 10.6.7).

        I’m assuming you won the battle, right? I changed to 10.8. 🙂

          Bret September 13, 2011

          Yeah it seems the way to go. I have seen a few other tutorials elsewhere doing the same thing.

          I followed yours step-by-step and it worked until I tried to install Lion. It gives me the option to install it now (since I changed it from 10.5.8 to 10.6.7).

          But for my current OS, I have Leopard.

          Bret September 13, 2011

          No change. I changed it to 10.7 and to 10.8

          Neither worked. I am stumped.

          Bret September 13, 2011

          It gives me the option to install it, but when i click on the icon to install it then i get the “The application Install Mac OSX Lion quit unexpectedly” pop-ups.

          Sidharth September 13, 2011

          How about Googling the error with double quotes?

          Really, I am as stumped as you are. And I really can’t think of any solution except stating the reason that the copy of Mac OSX Lion is corrupted.

          It’s hard to diagnose what the issue is, and there’s no way to replicate the issue from my end. But there’s hope with Apple community. You might want to post the issue in Apple’s Discussion board.

          I hope this is an easier fix. Keep me updated.

Leon Agusta July 31, 2011

oh nice post man,,,!!!!
i’am very stress now..
becouse my acer 4750 sandybridge can’t update to 10.6.8, and i wanna go to OS X LION directly,,
maybe my Intel HD 3000 graphics is available from OS X lion…
thank’s and regards!!!!!

Sunshine July 31, 2011

I can’t save the systemversion it says I don’t have appropriate access priviledges. How do I solve that?

    Sidharth July 31, 2011

    Have you logged in as Admin? That should do the trick.

    Paul August 9, 2011

    I was having that problem and I figured it out. You must change the access privileges for the folder that its in (Core Services). THEN you can save the file. Make sure to change back the settings.

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