Accidentally deleted Macintosh HD on my new MBAir and it won't start

Discussion in 'Mac Basics and Help' started by bluedevilbabe, Feb 1, 2015.

  1. bluedevilbabe macrumors newbie

    Feb 1, 2015
    So, I'm an idiot and decided to mess around with my Macbook Air that I bought TODAY. It all started because I decided I might as well use the file vault option it gave me while I was setting it up, but I had the same problem so many others have had, where it just continued to say that encryption was paused, whether I had it plugged in or not. I tried doing everything I could think of and it never changed.

    I read some forum post about going to disk utility and repairing your hard drive or wiping it and reinstalling OS X Yosemite so I fooled around with that a bit and it still didn't work. Finally I tried erasing something because I had read it and I obviously did not have a clue what I was doing and accidentally erased the "Macintosh HD" tab that was the encrypted tab (or whatever it is) that is indented below the very top Macintosh HD tab on the disc utility screen.

    Since I did that, my mac won't go to it's log in screen, it just goes directly back to the screen with the options to reinstall Yosemite and go to Disc Utility, etc.

    I tried to reinstall Yosemite after this and it says to pick a drive, but the only visible drive is "Recovery HD" and it is grayed out. Sometimes it looks "clickable" but then a message says, "Cannot be installed on Recovery HD".
    I also have no options under start up disc...

    I am so irritated with myself, and I'm really hoping someone here can help, because everyone seems so knowledgable! I also have NO time to get to the apple store because I work all day and need this laptop to work... what a disaster.

    Anyways, any advice would be greatly appreciated!
  2. mpainesyd macrumors 6502a


    Nov 29, 2008
    Sydney, Australia
  3. DeltaMac macrumors G3


    Jul 30, 2003
    I think you should simply boot to internet recovery, and do a complete reinstall.
    The internet recovery connects to Apple's servers, and downloads everything, without relying on anything that might be left on your hard drive.

    You may need to reset the partitions, using Disk Utility, then choose your hard drive, and change the Partitions Layout drop-down to 1 partition, then name your new partition whatever you like, and then click the Apply button.
    When that is complete - quit Disk Utility, and continue on with an OS X install.
  4. Dave Braine macrumors 68040

    Dave Braine

    Mar 19, 2008
    Warrington, UK
    I didn't think that a Mac could wipe/erase it's own hard drive? It had to done from an external source? That option is greyed out in Disk Utility on my Mac.
  5. DeltaMac macrumors G3


    Jul 30, 2003
    You can erase the hard drive if you boot to the recovery system, and run Disk Utility from there. It's all on the same hard drive, just booting to a different partition.
  6. Keter, Feb 3, 2015
    Last edited: Feb 3, 2015

    Keter macrumors member

    Jan 30, 2015
    I may be able to help....

    When you begin the encryption process you should have been provided an encryption key. After this is provided to you and you advance to the next section the encryption will begin. It can take a very long time too. Many get impatient and do a similar thing you have done.

    Here is the issue, if the disk is encrypted, and I do not think you can be partially encrypted, if you erase the contents of the disk or the partition you will not be permitted to mount and write to the encrypted disk until that key is provided or you can input the password to the Admin account that initiated FileVault.

    Once you can see the disk, you will need to partition with GUID and format to HFS+ with Journaling then reinstall the OS.

    Start with these steps:

    Verify if disk is encrypted from Disk Utility.

    1. If you are booted into Recovery, launch Disk Utility.
    2, From the left hand panel locate the main SSD disk, click on it so that it is highlighted, if there is no sub volume to the disk then it may be encrypted.
    3. If you find the disk may be encrypted, with the disk highlighted choose File from the Menubar, then choose Turn Off Encryption..., if that option is available for you to choose. (you will need that encryption key or your Admin password)
    4. If that option is not available then your disk is not encrypted, and you can simply choose the Partition tab and create a new one by clicking the drop down of Partition Layout: and change from Current to 1 Partition, provide the partition a name, format to Mac OS Extended (Journaling), then click Apply.
    5. Quit Disk Utility
    6. Begin Recovery Install, once you are provided the choice of where to install the OS, your newly created partition should be an option to install to.

    Worse comes to worse you can always call Applecare if you have coverage.

    BTW if you follow my method above you will not be able to recover any files from your computer, but you may have already done enough that your files are gone for good.

    PM me if you need more help. I am happy to assist you over the phone and can provide you my number.

    Here is a reference to unlock and decrypt a disk:

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6 February 1, 2015