Cannot install Snow Leopard from original Disc

Discussion in 'macOS' started by LeeTH, Apr 19, 2019.

  1. LeeTH macrumors newbie


    Apr 19, 2019
    Hello Everyone

    I found my Mid 2007 iMac struggling with El Capitan, so I decided to go backwards and install Snow Leopard.

    After about 10 mins the install stops and gives me a huge list of errors.

    Question is this:

    If I have to format the HDD could I back up what’s on it beforehand (I have my music I want to keep)

    Any help is appreciated


  2. Fishrrman macrumors P6


    Feb 20, 2009
    The VERY FIRST THING I would do is to use either CarbonCopyCloner or SuperDuper to create a cloned backup of your internal drive onto an external drive. That way, if something goes wrong with the data on the internal, YOU STILL HAVE AN EXACT COPY OF IT. DO NOT SKIP DOING THIS!

    Both CCC and SD are FREE to download and use for 30 days -- doing this will cost you nothing (except for the cost of the physical backup drive, if you don't already have one).
    The version of CCC you want to use is this one:
    Download CCC 3.5.7

    Next question:
    WHAT are you trying to "install from"?
    An installer app?
    An installer DVD?
    Something else?

    Your best bet would be:
    1. Create the cloned backup as stated above.
    2. Boot from your installer utility (this CANNOT be located on the internal drive)
    3. ERASE the internal drive -- NUKE it.
    4. Install a "clean copy" of Snow Leopard.
    5. You'll probably have to manually re-install your 3rd-party apps, and manually re-install your data files as well.

    Yes, it will be A BIG JOB.
    Better plan on a day or two to do it.
  3. LeeTH thread starter macrumors newbie


    Apr 19, 2019
    Hi Fishrrman

    First of all thank you for your reply I appreciate it.

    I am trying to install from the Snow Leopard original Disc (DVD) that I got with the iMac.

    Where would I get the clone app?

    As at the moment my iMac is in limbo so how would I run it. It’s my music I am most worried about so If I could back that up I’d Nuke the HDD.


  4. treekram macrumors 68000

    Nov 9, 2015
    Honolulu HI
    So - your Mac won't boot properly and you have no backup. Is that correct?

    If so, you're in a tough spot. There's a decent possibility that your HDD is having problems and if that's the case, then continuing to use may make the situation worse. It also could be the DVD reader or the Snow Leopard disks but to me because it appears you don't have a backup, you would need approach the situation assuming that the HDD is having problems.

    Do you know when the HDD was installed or is it original to the iMac? Do you have another Mac that you can use? Do you have empty external disks that you can use? How important is your data to you?
  5. Fishrrman macrumors P6


    Feb 20, 2009
    OP --

    Like tree said, do you have access to another Mac?

    Here's something else you could try:
    1. You will need an external drive, I think USB will do.
    2. Boot the iMac from the DVD install disc
    3. When you get to the installer, quit it and open Disk Utility (in the utilities menu?)
    4. Erase the EXTERNAL drive to Mac OS extended with journaling enabled
    5. Now quit DU and re-open the installer
    6. The installer will ask WHERE you want to install
    7. Select the EXTERNAL drive. See if you can get the OS installed onto that.
    8. If you can, boot from the external drive and create an account
    9. When you get to the finder, can you see the internal drive on the desktop?
    10. If so, it may be able to copy stuff from it, repair it, reinstall the OS to it, etc.
    But you may have to take the above steps first.
  6. LeeTH thread starter macrumors newbie


    Apr 19, 2019

    I don't have access to another Mac.

    If I formatted it would it then take the install from the disc (dvd)

    Thanks for your help

    --- Post Merged, Apr 20, 2019 ---
    HDD is the original one never been replaced

    I uninstalled El Capitan because it was lagging.

    Would the OS on a bootable usb work?
  7. Fishrrman macrumors P6


    Feb 20, 2009
    Try the instructions I provided in reply 5.
    Then get back to us.
  8. treekram macrumors 68000

    Nov 9, 2015
    Honolulu HI
    That's an old HDD. It may be OK but there's a good chance that it's having problems. There is software to test each sector of the HDD and determine how long it takes to write/read to each sector and see if there are problems or a slow response. The problem in your situation is that you need a working system to do that and the cost of the software would be not much cheaper than either a new HDD or new SSD.

    If you format the HDD and try installing again, it may work but you would lose the data on the disk.

    If you want to try to keep the data you have, the question is how much do you want to spend? In your situation, I would go to an Apple-authorized service shop, have them remove the HDD and do a quick check on whether it's working and has data on it. Have them install a SSD and put an OS on it. You may want try El Capitan again as it would work better off of a SSD than it did your old HDD. I'm guessing that would be $100 for the labor, $70 for a 500GB SSD or if you can make do with a 250GB SSD, it would be $30. This is just a guess and the SSD prices are for a name-brand SSD (other brands are not much cheaper) but it gives you an idea of what it will cost to get a functioning computer. You can try doing the repair yourself - take a look at the iFixit site: (20-inch) (24-inch)

    Note that this only gets your computer working. You'd have to try to recover the data which would require an enclosure or dock for your HDD - that would be about $25. If you can't easily copy the files once it's in an enclosure, then that would be additional costs and work.
  9. LeeTH, Apr 21, 2019
    Last edited: Apr 21, 2019

    LeeTH thread starter macrumors newbie


    Apr 19, 2019
    Treekram thank you so much for your help

    I have old back ups of the HDD in time machine. Would this be worth a go?

    I am in the UK, how much would you say for an SSD here?
  10. treekram, Apr 21, 2019
    Last edited: Apr 21, 2019

    treekram macrumors 68000

    Nov 9, 2015
    Honolulu HI
    Having TimeMachine backups makes a big difference in your options.

    While I think that your internal HDD is having problems, it's possible that just the OS files were botched and that your data is fine. It's also possible that you won't be able to restore from your TimeMachine backup. So a prudent action to take is to get an empty external HDD that is at least the capacity of your internal HDD and connect it to your iMac. Boot from your Snow Leopard disk and one option should be "Restore From Time Machine Backup". Instead of selecting your internal HDD as the target, select the external HDD and see if can restore to it. This process will like take a while to complete.

    If you need to buy an external HDD, you likely will have to format it for the Mac using Disk Utility which is an option when you boot from the Snow Leopard install disk. The Disk Utility app had a major makeover several OS versions ago so the following is a link of how it appeared in Snow Leopard. It was the first link I could find that had pictures - there's probably better examples but this will do. In the link, they start Disk Utility from a working computer - you're starting it from the install disk. You also have to be aware that this link was made for a specific product and to ignore references to that product. IMPORTANT. In step #4, select "GUID Partition Table" instead of "Apple Partition Map".

    To summarize on how to format a new external HDD:
    1. Open Disk Utility from the Snow Leopard install disk. At some point, it may say the drive is unrecognizable or something similar. You can ignore this message.
    2. Select the empty HDD - make sure to select whatever is to the left-most side that represents your external HDD. Make sure not to select your internal HDD or your Time Machine HDD.
    3. Select the "Partition" tab at the top and make sure "Volume Scheme" is set to 1 partition.
    4. Press on the "Options" button and select "GUID Partition Table".
    5. Set the format to "Mac OS Extended (Journaled)".
    6. You can name the disk if you wish. Press the Apply button.

    If you don't want to go through this step of trying the restore first on another disk, that would be your choice but again, it's possible that your internal HDD contains a good copy of your data (even if it can't boot) and that the TimeMachine restore will overwrite this data with nonsense.

    So if you do go through the step of trying out the restore and it works and the data is good, you can try to restore to your internal HDD.
    - If the TimeMachine backup is of what you had in El Capitan, you'll get El Capitan on your internal HDD.
    - If the TimeMachine backup is of what you had in Snow Leopard, you'll get Snow Leopard on your internal HDD.
    If your TimeMachine backup is El Capitan and you want to revert to Snow Leopard, you should restore to the external HDD, format your internal HDD, try the Snow Leopard install again and then you'd have to copy over your data. You might be able to use the Migration Assistant app but I'm not sure if that would work.

    So the prices in the UK for a SSD is £64 for near-top-of-the-line 500GB, £52 for a name-brand not-quite-as-good 480GB, £30 for name-brand not-that-fast 240GB. I don't want to hazard a guess as to what service costs would be in the UK.

    UPDATE: If your TimeMachine backup is not up-to-date, after you boot from the external disk (presuming the restore works), you can check your internal HDD to see if your data files are OK (It would probably be under /Users/[your login name]. You can copy whatever files at this point - but don't overwrite files on your external HDD - copy files from your internal HDD to some other directory on your external HDD in case the files on the internal HDD have been corrupted.
  11. LeeTH thread starter macrumors newbie


    Apr 19, 2019
    Thank you it means a lot to me to take the time to help Me I will try it
  12. LeeTH thread starter macrumors newbie


    Apr 19, 2019
    Hello all

    I looked at the backups and then remembered I have most of my music in a folder. So I nuked the drive and tried the re-install from the DVD and it worked!! Just have to re-install my printer drivers etc and apps. I imagine al have a very speedy Mac now back on Snow Leopard? Thank you to you people for the help. Couldn’t of done it without you.

    Thank you so much for your time and help. Means a lot to me.

  13. treekram macrumors 68000

    Nov 9, 2015
    Honolulu HI
    I'm glad it worked out for you. But you do have an old HDD so you should make sure your backup is kept current and consider having 2 separate backups instead of one. You can follow the suggestion in post #2 - CCC is a nice, easy-to-use app but it does cost money if you're going to use it on a continuing basis ($40 here in the US). SuperDuper is a bit less (I haven't used it). You can also keep a second TimeMachine backup.

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12 April 19, 2019