Install OS X Snow Leopard from a USB flash drive

By Dan Hinckley

536 responses. »

The steps below will guide you through how to Install OS X Snow Leopard from a USB Flash Drive. Alternatively, you can also read these instructions on how to install OS X Lion from a USB Flash Drive.

Apple officially released Snow Leopard a couple years ago and consumers can still find the latest version of OS X at Apple Stores and resellers across the country.

At version 10.6, Snow Leopard, focused more on improving speed and performance than adding new features to OS X. With the operating system available to customers, individuals are ready for their upgrades.

Installing OS X From a USB Drive

Like other versions of OS X, Snow Leopard can be installed from a USB drive. This is especially beneficial to Macbook Air users looking to install the OS without a DVD drive. To do this, you’ll need to prepare your USB drive with the installation files. Like many of our other Mac Help articles, the steps listed below worked particularly for Snow Leopard but should also work for installing OS X from USB on Leopard.

The installation files sit at 6.2gb on the Snow Leopard DVD, so you’ll probably need a drive that has at least 8gb available. If you want your installation files to last against the elements, check out this 8 GB Water/Shock Resistant USB flash drive.

After you’ve gotten the correct USB device, connect it to your Mac and prepare it with the Snow Leopard installation files by following these steps:

NOTE:Depending on your flash drive, you may need to follow steps 5 – 7 on installing onto a USB drive to make sure the drive is bootable before you get start. This includes updating the options for the partition so that it is set to a GUID partition. If the USB drive is not bootable you will NOT be able to install from it.

  1. Open Disk Utility and select the Flash Drive
  2. Select the Erase tab on the right and then set Format to Mac OS Extended (Journaled). Name the partition you’ll be creating Snow Leopard or OS X Install so you can keep track of your installation device. After you’ve done this, click the Erase button.
  3. UNTITLED 1.png
  4. After Disk Utility finishes erasing your old data on the flash drive and setting it as a new partition, it will be ready for the Snow Leopard install files. Select the Restore tab at the top and then drag the Snow Leopard DVD to the Source field. Select your USB device for the Destination file. Click Restore and wait for the restoration to finish (about 20 minutes).
  5. Disk Utility-1.png
  6. If the restoration worked correctly you should be able to open your USB device and see the Leopard installation files. If you try and click the Install OS X Snow Leopard icon, you’ll get the message below telling you you can’ install OS X from this volume. IGNORE the message. The next steps will walk you through the installation steps.
  7. Install Mac OS X.png
  8. Now that the installation files are successfully on your USB device, be sure to remove the Snow Leopard installation DVD from your drive. Next, restart your Mac and when it first starts to reboot, be sure to hold down the option (alt) key on your keyboard. After a few seconds at least two volumes should appear for you to select from for installation. One of those will be the USB drive we just prepared. Select it.
  9. After the Snow Leopard installation software boots from your USB drive, follow the on screen instructions for installation. It took about 38 minutes to install Snow Leopard on my machine from the USB drive. I’m curious to see how this compares to the average Mac users, please leave a post in the comments letting us know how long it took on your machine.
  10. After the installation finishes, it will reboot your computer into your new upgraded version of OS X, version 10.6 Snow Leopard
  11. About This Mac.png

This method works for installing OS X Snow Leopard onto a Mac from a USB Drive. It should also work for installing Leopard or other older versions of OS X on Intel Based Macs. Check back often for additional help and tips for your Mac.

About Dan Hinckley
Dan Hinckley is an experienced Mac user who converted to Apple products when they introduced them on Intel Processors. He loves helping others get more out of their devices! Subscribe to to get the latest from Dan and the Maciverse Team!! Find out more about Dan:

536 Responses so far.

  1. Marcus

    September 10, 2012 at 9:00 am

    Took me about 20 minutes now to install.

  2. icke

    September 11, 2012 at 12:17 pm

    works perfect. thx a lot.
    took me about 40 mins to install osx 10.6 from usb-drive on mac mini 2.1 2ghz 3gb ram.

  3. Bebbi

    September 14, 2012 at 3:57 pm

    Making the USB worked. I used my MB Pro and the 10.6.4 disk that came with my iMac. The iMac is formatted, nothing on it. Done in Target-mode with firewire. The iMac HD still shows up on my MB Pro. Whanted to try to use the USB solution because when booting with orginal DVD on the iMac I can clik on the DVD icon but then nothing happes. The screen just goes blue/grey and no process is going on, just the DVD drive making strange noises. When booting the iMac with the USB I see the USB icon and i click on it and wollah nothing happens. The screen just stares at me with its blue/gray face…. PLEASE HELP

  4. Joe

    September 15, 2012 at 6:21 pm

    thanks for your help. it took 26 minutes to download snow leopard. then upgraded to mountain lion.
    yippee ki yay mf!!

  5. Gab

    September 25, 2012 at 1:41 pm

    I followed every step several times. I am trying to install on a blank SSD Intel. I see the OSX image on my flash drive whwn holding the ALT button, but that's about it. When I click it, nothing happens…



  6. dev

    September 28, 2012 at 8:50 am

    awesome man… you just explained how to create a bootable MacOS USB flash drive… IN…. MacOS(supposedly down and needing reinstall… )

  7. Tanner Rosen

    September 29, 2012 at 10:32 pm

    Your a genius! This worked for me and its installing. Thankyou!

  8. Amy

    September 30, 2012 at 1:09 am

    Thanks for the guide!! Worked great! Took about 40 minutes. Is it possible to tell me how I can get the USB back to its original format? (I am horrible with IT)

  9. Matt

    October 2, 2012 at 4:03 am

    Worked perfectly without a hitch. Tyvm for your effort. :)

  10. Barry Rudd

    October 4, 2012 at 9:25 am

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  11. Max Serraty

    October 9, 2012 at 8:08 pm

    it took me 25 minutes and how do i undo what i did to my usb drive?

  12. Prod'cer Dre

    October 10, 2012 at 1:44 am

    it has jst worked perfect for me bt ma display has failed wat could be da cause?

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  15. haz

    October 26, 2012 at 1:58 am

    I do the first few steps alright and when i get to the step of the restore half way through it gives me a message that says Device removal and i havent removed the USB??

  16. brain

    November 1, 2012 at 5:53 pm

    Took 3 hours to prepare the usb estimated time for install 45 minutes

  17. Zach

    November 16, 2012 at 10:19 pm

    All I get is a cross out sign after rebooting from the usb drive. Whats wrong?

  18. Ray

    November 23, 2012 at 4:53 pm

    I'm getting the same error using the dvd drive. How do i fix it?

  19. Sadaf

    November 29, 2012 at 9:46 pm

    Hi-I have a 14.9 Dane-Elec flash drive and I followed all of the directions and was on the final step and a message comes up that says "Restore Failure-Could not restore: Operation not supported"

  20. consultant

    December 1, 2012 at 2:37 am

    This is a good post. This post gives truly quality information. I’m definitely going to look into it. Really very useful tips are provided here. Thank you so much. Keep up the good works.

  21. Lisa

    December 6, 2012 at 5:36 am

    Everything installed and worked great (10.5) until it made me restart.. And every time i restart to turn it on it says must restart and doesn’t let me past the apple start up. What’s going on?

    • @rzahrai

      January 20, 2013 at 5:30 pm

      You may be installing on a newer Mac machine, which prevents downgrades. I'm doing the same, but I'll have to take my hard drive out and follow these steps on an older machine, then re-install the hard drive back into my new MBP. I hate Mountain Lion, but the newer machines won't let you boot from a Snow Leopard DVD or USB. If I'm wrong could someone please correct me.

  22. Nate

    December 12, 2012 at 8:42 am

    Working on bringing a 2008 macbook pro to Lion…used this site to first install 10.6. Worked like a charm, took 42min. Thanks

  23. Erica

    December 13, 2012 at 2:01 am

    38 minutes!!! Thank you! :)

  24. Mythos

    December 18, 2012 at 2:19 pm

    HOw long should it take to boot once the Flash Drive is Targeted to be the startup disk? I restarted and it begins to boot and the Apple Symbol appears and sems to not be going anywhere. I know that Flash Drives Load slower than a DVD or Hard Drive, Just do not want to wait to long if it is not working. If only i knew if my flash drive was accually reading it woudl help or if a load icon was on the screen lol. But as i have no indications of anyting hapening I think maybe it is not working …

  25. C.DE

    December 21, 2012 at 8:39 pm


    Followed these steps and the update worked. Now running OS X 10.6.3 on my late 2007-ish MacBook Pro.

    One problem though, now I cannot connect wirelessly to my router. Airport is connected to my network, and I have used the Network Utility and 'Ping'-ed my router successfully, but at the moment I still cannot connect. :(

    Any advice?

  26. Eric

    December 31, 2012 at 10:19 am

    This worked perfectly, thanks! Took 42 minutes on a 2006 iMac 2.16 GHz core2duo.

  27. vsc

    December 31, 2012 at 7:35 pm

    I have 2 Intel iMacs that I purchased within a year of each other. I’ve wiped one completely and have been trying to boot with the formatted 10.6 USB drive with no luck. I’m just seeing the logo and it appears that it’s trying to load but does nothing.

    The other iMac has 10.5.8 installed and I’m able to load the 10.6 USB drive with no issues.


  28. Khalid

    January 5, 2013 at 9:56 pm

    Worked perfectly for me! Thanks. :)

  29. leevanbeef

    January 6, 2013 at 4:32 pm

    I have an old macbook with a dead DVD drive and a blank hard disk. I don’t have anything running OSX, is there any way to do this using a windows PC? I have a snow leopard image, but no dual layer DVDs or an external DVD drive on hand (I remember installing OSX using an external DVD drive on a friend’ mac air, so I suppose I could do that if a USB won’t work). Thanks.

  30. Anna

    January 6, 2013 at 8:47 pm

    I read through some of the comments here, seems to work. However, do I need to format my HD before I do the installation?

  31. Chavo

    January 16, 2013 at 7:06 am

    GRACIAS! desde México funciona perfecto, Thanks a lot from Mexico it works like a charm!

  32. Diego

    January 20, 2013 at 12:46 pm

    Hi Dan

    I have installed it in a Macbook Pro but when the laptop went to restart then the grey screen never change and the "counter clock" was working for hours.

    I've tried to install a previous version, but also the latest one (10.8.2) but now when I press the ALT button, my USB stick never appears, and only two volumes are visible (HDD and Restore). What can I do?


  33. @rzahrai

    January 20, 2013 at 5:29 pm

    Brilliant steps, but I don't think this method works with the newer Macbook Pro's (2012 onwards); the new MBP just won't let you boot from a Snow Leopard USB or the original DVD – must be programmed to refuse the downgrade. Sucks. Think I'll have to downgrade HD on an older machine, and then reinstall the HD back into my 2012 model.

  34. Renny

    January 22, 2013 at 7:24 pm

    This was an amazing article to find! I got a Mac Mini for free from my job and it was old and hadnt been used since 2009. It was running 10.5.8 i believe and i couldnt upgrade any software and ordered the snow leopard install disc. Once it arrived i found the DVD drive to be dead. With these instructions I was able to install the upgrade with NO PROBLEMS. I am not a Mac user normally so i was frightened about screwing something up. I just wanted to say thank you for saving me a lot of hassle tracking down an external disc drive. Awesome!

  35. Marie

    January 27, 2013 at 3:01 pm

    I pressed alt after restarting and chose the drive with my installer on it. Does it naturally just take long?

  36. miki

    January 31, 2013 at 1:36 pm

    thank you so much for the instructions!!! worked perfectly and so easy to understand. saved me a trip to the Genius Bar ;)

  37. Daniel

    February 8, 2013 at 10:04 pm

    I've done all the instructions but when I restart and run it I get this error message saying, "You need to restart your computer. Hold down the Power button until it turns off, then press the Power button again." I've tried with several different devices but they all have the same problem. Help?

  38. Miguel

    February 15, 2013 at 6:41 am

    Worked Fine !!! After choosing the USB to boot, the screen turned black, like the Mac was turned off but its some protection. I pointed a flashlight to the sreen andmanaged to complete the instalation.
    Thanks for the great tutorial.

  39. Blue Hawaii

    February 17, 2013 at 9:46 pm

    Worked as instructed! Thank you!

    I used a SanDisk thumb drive with a retail OS (torrent).

    iMac 2.16 GHz Intel Core 2 Duo
    1 GB 667 MHz DDR2 SDRAM

  40. Daniel

    February 25, 2013 at 6:30 am

    Hello everyone. I'm running Lion at the moment and my superdrive doesn't work anymore.
    Is it possible to reboot my Mac with Snow Leopard? (I already boot Snow Leopard on a 8GB flash drive, but once I press alt key on startup I follow all the steps, until I can't select my computer drive to install…probably because there's still Lion inside??)
    Any help?

  41. JesseKnows

    February 28, 2013 at 11:20 am

    See… for another point: for the Restore to be allowed, you need to unmount the USB volume (not the drive!).

  42. trifucostin

    March 6, 2013 at 4:28 pm

    Hello , i have a brand new sealed 120 ssd ( instaled on my macbook white , what steps i have to make before i instal the leopard from usb ?
    I olso have the old hard drive 160 gb with 10.5.8 version but i dont want to use anymore ,

    If i have this configuration on mackbook white :
    Processor 2,4 Ghz Intel Core 2 Duo
    Memory 4 gb 667 Mhz ddr2 SDRAM
    Hard drive: ssd 120 gb
    I can instal the lateast version of Lion ?

  43. Nick G

    March 15, 2013 at 5:46 pm

    It seems to have wiped everything else from my external hard drive!?!?!? i.e all movies, music, photos, files…

    really desperate for some help!?????

  44. Yasser

    March 24, 2013 at 10:40 pm

    I made a bootable usb disk and installed it too. Now the problem that I have is I can no longer use the Pendrive to share things on windows. Please advice on how to restore the pendrive back into its original format.

    • Navid

      March 29, 2013 at 4:38 pm

      Yasser, Windows cannot understand Mac disk formats. You need to re-format the drive to FAT format. You can do this from Disk Utility.

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