HELP! Windows has damaged Macintosh HD

Discussion in 'Mac Basics and Help' started by saguerra, Mar 22, 2016.

  1. saguerra macrumors newbie


    Mar 22, 2016
    Espinho, Portugal
    Hi folks,

    I really need some expertise on this one!
    I had OS X El Capitan and Windows 10 (bootcamp) installed on my MacBook Pro.

    Today i tried to boot Windows, and a screen appeared saying it couldn't boot, so i used windows 10 installation disk to "Fix Startup Problems". After it supposedly fix the issues. I can't boot either on OS X or Windows.

    When i boot and press "Alt" only shows OS X, but when i select it, the screen goes black and nothing happens, not even Apple logo (tried to boot on Safe Mode, reset PRAM, and nothing fixed that).

    I booted with a OS X install USB and opened Disk Utility, and now instead of two partitions with Macintosh HD and BOOTCAMP it only shows "Untitled".

    Here are a few screenshots:


  2. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    You may have a failed drive that caused this. At any rate, what you have now is your internal drive formatted completely in NTFS for Windows. In that top screenshot go to the erase tab and format the internal to Mac OS Extended (Journaled) then reinstall OS X. This will of course erase everything on the drive, so hopefully you have backups.
  3. saguerra thread starter macrumors newbie


    Mar 22, 2016
    Espinho, Portugal
    That "Untitled" partition that shows on the first screenshot has only 500mb, it belongs to windows.

    If you check the terminal log on the second image, on the 6th row it lists 0xAC --- 205.3 GB disk0s2, that was suppose to be the Macintosh HD.

    I just don't get how could the "Statup Repair" from Windows 10 installation disk format the partition to NTFS. Don't believe that's what happened.

    I know i can get OS X back up an running by formatting the hard drive, but i have a lot of important files that i don't have any backup :/
  4. RogerWilco macrumors 6502a


    Jul 29, 2011
    Never do any kind of disk maintenance or transfers without two known-good, current backups. IMO OSes should have a dialog that asks about backups and warns people of the possible consequences.
  5. Mousse macrumors 68000


    Apr 7, 2008
    Flea Bottom, King's Landing
    It's be over a decade (nearly 2) since I fixed computers for a living. So take my advice with a grain of salt. I'm the equivalent of a chuck wagon repair guy giving advice about cars.:p:p If you have a Quadra/Centris/Perfroma/PMG3/PMG4 that needs work, I'm your man.;)

    Anyhow, it seems to me Windows rewrote/overwrote your GPT (GUID Partion Table).o_O The GPT is like a map of your HD that the computer uses to find stuff on your HD. Back in Classic MacOS days, I would have ran Norton Disk Doctor. Dunno of there are any commercial programs to fix a GPT these days. If not, your only real option is spending mucho dineros (a few K's) for data recovery service.

    Here's your problem, your fancy new motor-car doesn't have a hitch to attach your horse.:D:D:D
  6. chscag macrumors 68030


    Feb 17, 2008
    Fort Worth, Texas
    Believe it, because that's exactly what happened. Weaselboy is correct. Never use a Windows install disk to repair Windows when you're dual booting with OS X. Next time make a backup of your Windows partition using WinClone and your OS X installation using CCC or SuperDuper. Follow the advice given by Weaselboy and start over... :(
  7. IowaLynn macrumors 65816


    Feb 22, 2015
    BCA does not create Windows GPT and MBR.

    Before doing anything, use CCC to clone the Mac, and WinClone or Paragon to clone Windows.
  8. Fishrrman macrumors P6


    Feb 20, 2009
    OP wrote:
    "I know i can get OS X back up an running by formatting the hard drive, but i have a lot of important files that i don't have any backup :/"

    You have just learned why one must keep backups.

    Go forth from this day and learn -- a sadder, but wiser man!


    What I might try in this situation (chances are it won't work, but I'd try it anyway):
    - Reinitialize the ENTIRE drive into ONE Mac partition using Disk Utility
    - Use a data recovery app such as "DataRescue" to scan the re-initialized drive to see what it finds.
    - Save the recovered data to a scratch drive.

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