Reader Tip: Run Lion 10.7 Developer Preview on Unsupported Core Duo Macs


Lion Preview running on Core Duo Mac

For those of you who like living on the Bleeding Age – while running on older hardware – Cult of Mac received this tip from reader Matt Briggs about getting his Core Duo based MacBook running the Lion Developer Preview installation of Mac OS X 10.7:

I managed to get the Lion preview running on a supposedly unsupported Macbook Core Duo from May 2006.

I installed Lion on a USB drive hooked up to a Mac Mini Core 2 Duo 2009, then removed /System/Library/CoreServices/PlatformSupport.plist and the same drive booted in the Macbook with no issues!

there might be some stricter restrictions in the future, but pretty good right now!

IMPORTANT: This is an unverified tip of an unsupported configuration. Use a spare hard drive for any tests, do not overwrite your primary system. This capability may not last in the official release versions.

I don’t have a Core Duo system myself to test this, so if anyone can duplicate these results on their own system please let us know in the comments.

  • Ben

    I installed 10.7 Lion on my late 2008 macbook pro with a core 2 due without a hitch. I didn’t even know there was an issue installing it on them. I just mounted the disk image on my desktop and it went ahead an performed the upgrade.

    On a side note, anyone wanting to downgrade back to Snow Leopard, you cannot simply put in the SL install disk and downgrade. Restart your computer and hold down C when booting, this will force it to boot from the CD. Again it will not let you install SL over Lion, it just gives an error message. What I did was select utilities from the menu bar and did a restore from a time machine backup. Anything you have changed or created up until this point will be lost (so copy these files onto a external drive) as Lion does not seem to perform time machine backups to a disk that already has SL backups on it.

    10.7 Lion is still VERY buggy as you would expect, but there are some great new features that I am missing a lot. I will install again after a few beta stages.

  • trex67

    What ARE the minimum system requirements for Lion? I’ve looked and can’t find anything online.

  • Adam Rosen

    Core 2 Duo processor or later:

  • Yacko

    “2008 macbook pro with a core 2 due(o)”

    The issue is with the Core Solo Mac Mini and the various Core Duo models Apple released. Not the Core 2 Duo model you mention. It’s about 32-64 bitness.

  • Aaron Williams

    I was able to connect a USB drive to my early 2008 MacBook and install Lion onto that drive. Booted up off of the USB drive, removed the PlatformSupport.plist file. Then connected the USB drive to my Core Duo 1.83GHz iMac (early 2006). Took a little while to boot, but booted right up. This is awesome!!!

  • Ben


  • racer

    I can confirm this works.

    Just tried it on my late 2006 20′ Core 2 Duo iMac (which previously would not boot Lion).

    Great Tip!

  • Bradley Greene

    Core Duo… Core 2 Duo machines should run this unmodified…

  • orbitly

    I can’t find PlatformSupport.plst in my CoreServices folder on my Mac, can you tell me exactly what the path is, or better do a youtube tutorial and send me a link?

  • orbitly

    There is no such file as “PlatformSupport” on my MacBook core duo black.

  • orbitly

    Please, someone give me a guide! There is no platformsupport.plist on Mac OS X 10.6.7 or 10.6.6!

  • Adam Rosen

    HI Tyler, the ony info we have it what was reported above. Full path to the file you’re lookng for (on the new Lion DP1 install) should be:


    As noted this is an unsupported configuration and I have no way to test directly myself.

  • TheThreepwood

    No, there won’t be, the platformsupport.plist will either be in the Install disk for OS X 10.7 or on the installed OS X 10.7 system.

  • Carpediemi24

    I have Lion DP 3…found the PlatformSupport.plist  doc, but it is in read only mode and I am the Admin…how can I delete it??  I have a plist editor but still says cannot save on this volume.

  • Guigeek

    Hello! did you get DP3 working?? I just tried to, but it only installs mac os x install data on my usb key, then trying to start it on the unsupported mac tells me, from boot.efi, unsupported CPU.. And I don’t find PlatformSupport.plist
    Perhaps I missed sth??

  • Carpediemi24

    Not yet. Believe it to be the boot.efi file.  Turn on invisible files then play around again and will find the plist.
    I copied every thing in folder and dragged to new folder so i could get past ready only mode. I am no developer, just like tinkering.
    I am going to wait until final release, should be next week or so, and play with that file:)

  • gilles vollant

    I think we will never be able run really Lion GM on a pure Core Duo MAc because some component (Finder…) are be 64 bits only.
    The question is more : running Lion on a Mac selled with Core Duo, but upgraded with Core 2 Duo. We have to remove somes hard coded computer ID exclusion

  • Jas Istheone

    A better way then removing the plist for supported platforms is to add your board id into the plist. Also there is some restrictions in the osinstall.mpkg for lion gm. you will need convert the .dmg to a .cdr. then you will have to use flat package editor to extract the distribution file from osinstall.mpkg. open it with text editor and add your board-id into the issupportedplatform function. also edit is64bit to return true. this is64bit function is checking your efi not your cpu. put the distribution file back into the osinstall.mpkg. Also edit the installable machines plist and platform support plists on the .cdr with your board-id. 

    With these edits you can install Lion on your core duo / 32bit efi Mac without issues. You should install lion to a second hdd/partition as you will need to re-edit the platform support plist after lion installs. Leaving this plist in place with the edit should help your mac survive updates as the plist is there so it won’t get reinstalled. deleting the plist could come back to haunt you on updates.

    Good luck and Enjoy!

  • Luis Enrique Besa Vial

    I’ve just upgraded to Lion and now Preview crashed right after starting, even if I just start it without content. What can I do?

  • Carlyle Danforth

    There is no such file on my imac core duo(upgrded processor to core2duo) @a4bbf52c2c50c3c0728ac67ae5f9d291:disqus /System/Library/CoreServices/PlatformSupport.plist
    I’d just like to see if lion works but install says not supported and quits help

  • rudi3700

    Nice tutorial! But will the Finder work? Because from what i have reading its an only 64 bit app….

  • Jacob Nash

     you go into disk utility, and select new image, then select apple; single partition, then select the size as 4.6, then select read/write disk image as the image format and when it is finished, click the image you just made and click the restore tab, then drag the image you just made into the destination box, and then drag your lion install image that you have into the source box. and select erase destination if not already selected, then click restore, and when it finishes, click open, and delete the file from the newly made disk image, and clear the trash bin. and there you go, :) it works!

  • Michael Miller

    Can we get any sort of confirmation about the upgraded processor imacs? Replacing the core duo with the core 2 duo was one of the reasons in doing this, but to get lion running do we merely need to follow these same instructions?