LordVoss

Q: Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks

Hi, so I recently decided to partition my hard drive and install Windows 8.1 to my Macbook Pro Late 2011 model.

I have managed to avoid installation via the optical drive and have been using a USB. After receiving this error (and after formatting right there with what they give me) I go back to my disk utility and erase the partition after changing it to exFAT and go back to the Windows partition to see if it worked but, nothing changed. Can anyone out there tell me what I need to do to fix this? Or how to change the MBR partition table to GPT? Thanks!

MacBook Pro (15-inch Late 2011), OS X Yosemite (10.10.4)

Posted on Aug 14, 2015 6:29 PM

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Q: Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be instal ... more

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  • by Loner T,

    Loner T Loner T Aug 14, 2015 6:53 PM in response to LordVoss
    Level 7 (24,307 points)
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    Aug 14, 2015 6:53 PM in response to LordVoss

    1. Was the partitioning done by BC Assistant or Disk Utility?

    2. Is your Optical drive not functional?

    3. You may have a partial EFI-based installation, which may no work properly on your 2011 MBP?

  • by LordVoss,

    LordVoss LordVoss Aug 14, 2015 6:57 PM in response to Loner T
    Level 1 (1 points)
    Aug 14, 2015 6:57 PM in response to Loner T

    Thanks for the quick response!

     

    I partitioned using Disk Utility.

     

    My Optical drive is functional.

  • by Loner T,

    Loner T Loner T Aug 14, 2015 7:09 PM in response to LordVoss
    Level 7 (24,307 points)
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    Aug 14, 2015 7:09 PM in response to LordVoss

    Your Mac (and Macs prior to Late 2013 which run EFI v 1.1) are considered preUEFI and do not support Intel UEFI 2.0 specifications. On such Macs, Windows is installed using BIOS emulation and a MBR and GPT in sync, which is known as a Hybrid MBR. As Macs have gotten closer to the Late 2013, they have supported more and more of UEFI 2.0 specs. 2010 Macs may support 50%, but 2012 macs may support 80-90% of specs. Full 100% support started in Late 2013.

     

    The UEFI specification supports GPT-only disks and W7/W8 also had partial support, but W10 is also now fully 2.0 compliant.

     

    On your Mac, the hardware exposed to Windows is controlled by an emulation layer called CSM-BIOS.

     

    My recommendation is to remove the current partition using Disk Utility, run BCA and let it partition (create the MBR) and allow a BIOS installation to complete. GPU and Audio are the most sensitive to such controlled exposure of hardware. EFI will not always see all hardware properly on such machines. You will need to create a physical DVD fro your Windows ISO.

  • by LordVoss,

    LordVoss LordVoss Aug 14, 2015 7:11 PM in response to Loner T
    Level 1 (1 points)
    Aug 14, 2015 7:11 PM in response to Loner T

    Ok...so remove the current partition. Create a new one through BC and allow a BIOS installation to complete? How do I do that?

     

    Also, I've read that if I use shift + f10 in the windows installer window I can convert the drive to GPT. Will this work for me as well? I have all of my data backed up on an external.

  • by Loner T,

    Loner T Loner T Aug 14, 2015 7:16 PM in response to LordVoss
    Level 7 (24,307 points)
    Safari
    Aug 14, 2015 7:16 PM in response to LordVoss

    On your Mac you do not want to convert to GPT, because of EFI-related issues. Please see How to install Windows using Boot Camp - Apple Support for BC Assistant based installation steps. This is another helpful link Use Windows 8.1 on your Mac with Boot Camp - Apple Support .

  • by M Compas,

    M Compas M Compas Aug 15, 2015 1:27 PM in response to Loner T
    Level 2 (215 points)
    Aug 15, 2015 1:27 PM in response to Loner T

    Last weekend, after searching high and low, I was able to do a clean install of Windows 10 on my Late 2013 Mac Pro (OS X 10.10.4). My primary issue was that in Boot Camp Assistant (v5.1.4), the option to "Install or remove Windows 7 or later version" was (and still is) greyed out. I, like LordVoss, had used Disk Utility to create a Windows partition formatted as FAT.

     

    Boot Camp Assistant had successfully created the Windows install USB key, and I was able to boot into the Windows installer. It was when I tried to format the Windows partition to NTFS did I run into the MBR/GPT issue. I found and installed a OS X command line utility 'gdisk' which changed the hybrid MBR data to allow Windows to install properly. All details are noted here: http://superuser.com/questions/508026/windows-detects-gpt-disk-as-mbr-in-efi-boo t

     

    After using 'gdisk' and rebooting back in the Windows install, the drive formatted without a hitch and I was up and running Windows 10 in no time. I would like to note, and I doubt this has any bearing on my successful install, but I did install rEFInd before I found and installed 'gdisk'. I mention this because I upgraded the bootcamp drivers in Windows last night – to the newly available Boot Camp 6 drivers – and I wasn't able to boot back into OS X. I did see some articles about rEFInd and slow boot times, and I suspect rEFInd as the culprit, but that's a completely different discussion on its own.

     

    My main concern, Loner T, is what option do I have besides creating a partition manually in Disk Utility, if Boot Camp won't create the Windows partition for me?

  • by Loner T,

    Loner T Loner T Aug 15, 2015 1:53 PM in response to M Compas
    Level 7 (24,307 points)
    Safari
    Aug 15, 2015 1:53 PM in response to M Compas

    On Macs with built-in Optical drives (with a few 2012 Macs as exceptions), a physical DVD must be readable and in the optical drive for that option to be enabled. You mention as 2013 Mac, as noted in my previous response, these models will support a direct installation using EFI boot and a Disk Utility-created Free Space partition. This Free Space will get split into an MSR and MS Data partition by the EFI installer.

     

    Using Gdisk to create an MBR forces a legacy BIOS installation on such (and later) Macs. rEFInd is a Bootmanager/Bootloader and is really not necessary on a Mac which already has a built-in Apple Bootmanager. If you use multiple OSes, then rEFInd is very helpful.