lion10

Q: The ultimate way to install Windows 8.x in (U)EFI mode on Apple systems

Well, all these solutions regarding Windows 8 (or 8.1) installation methods in this forum seem to be quite complicated. Here follows my favourite way for installing Windows 8.x on Apple EFI systems.


 

First, once and for all, forget Boot Camp! Because Windows 8 is fully EFI compliant, Boot Camp is totally useless. You only need it to get all the Windows drivers. When using Boot Camp with Windows 8 in EFI mode you get very likely even greater problems. The root of the most Windows 8 install errors reported here is located in Apple’s special "hybrid MBR" GPT layout. Nothing else!


 

So, in consequence, you have just to remove / replace that "hybrid MBR" with a standard GPT "protective MBR". This change will NOT affect OS X or any other OS X program in any way!


1. Use the OS X Disk Utility to create a partition scheme of your wishes.

 

2. Download in OS X the tool "GPT fdisk". Install it and start it in terminal with:

    sudo gdisk /dev/disk0 or sudo gdisk /dev/disk1

 

    Type p to view the partition table (verify that you have selected the right drive)

 

    Type x to enter experts menu

 

    Type n to create a new clean "protective MBR" (GPT fdisk will NOT report any changes)

 

    Type w to save your changes

 

 

3.  Start Windows 8 setup in EFI mode; - switch to "Windows prompt" under "repair tools". Start command diskpart. Check your partition; - select that one with name "EFI". Add the drive letter "b" with the command assign letter=b. (Note, this point is perhaps not needed at some systems.)

 

 

4. Exit diskpart, start again Windows 8 setup installer from prompt with command setup.

 

 

In Windows setup you have now just to format the Windows partition, - the setup installer is now able to update the Apple EFI Boot record properly. You should not get the "Windows could not update the computer's boot configuration. Installation cannot proceed." message.

 

 

I can confirm that this install method has worked perfectly for several MacBook, iMac and Macmini computers. Furthermore you should be also able to install Linux smoothly with EFI mode in dual or triple boot configurations. (Don’t know but Linux may have the same troubles like Windows with Apple’s "hybrid MBR" GPT layout.)

 

 

Finally big thanks to Roderick W. Smith for his great GPT fdisk tool!! And also a big thanks to user "riseyth" which has given the diskpart EFI "assign letter =b" hint in this forum. (list of references: http://superuser.com/questions/508026/windows-detects-gpt-disk-as-mbr-in-efi-boo t/508454#508454)

Posted on Apr 16, 2014 11:58 AM

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Q: The ultimate way to install Windows 8.x in (U)EFI mode on Apple systems

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  • by Loner T,

    Loner T Loner T Sep 2, 2015 5:02 AM in response to Ole_Oie
    Level 7 (24,307 points)
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    Sep 2, 2015 5:02 AM in response to Ole_Oie

    On a 13-in 2012 MBP, I have AHCI working using BIOS/MBR installation and sound also works properly.

     

    W8.1-AHCI-Samsung840Pro.PNG

  • by Ole_Oie,

    Ole_Oie Ole_Oie Sep 2, 2015 6:23 AM in response to Loner T
    Level 1 (6 points)
    Sep 2, 2015 6:23 AM in response to Loner T

    I might try to install it again with bootcamp.

    Thank you.

  • by hoosentroger,

    hoosentroger hoosentroger Sep 21, 2015 3:56 AM in response to lion10
    Level 1 (0 points)
    Sep 21, 2015 3:56 AM in response to lion10

    Found valid GPT with protective MBR; using GPT. (NOT HYBRID MBR!!!)

    this is what gdisk is telling me in terminal and still i keep getting various error messages at the end of windows 10 installation (2014mid 15' retina macbook pro, yosemite) i assigned/unassigned letter b/ letter s to the efi "system" partition, created the mrs reserved 128mb partition in diskpart, and still "windows couldn't update the computers boot configuration" then "windows couldn't prepare the computer to boot into the next phase of the installation"

    gpt show: /dev/disk0: mediasize=500277790720; sectorsize=512; blocks=977105060

    gpt show: /dev/disk0: PMBR at sector 0

    gpt show: /dev/disk0: Pri GPT at sector 1

    gpt show: /dev/disk0: Sec GPT at sector 977105059

          start       size  index  contents

              0          1         PMBR

              1          1         Pri GPT header

              2         32         Pri GPT table

             34          6        

             40     409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

         409640  741565040      2  GPT part - 48465300-0000-11AA-AA11-00306543ECAC

      741974680    1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

      743244216       1608        

      743245824     262144      4  GPT part - E3C9E316-0B5C-4DB8-817D-F92DF00215AE

      743507968  233596928      5  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

      977104896        131        

      977105027         32         Sec GPT table

      977105059          1         Sec GPT header

     

    please help!

  • by Loner T,

    Loner T Loner T Sep 21, 2015 7:29 AM in response to hoosentroger
    Level 7 (24,307 points)
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    Sep 21, 2015 7:29 AM in response to hoosentroger

    Your are using EFI Boot.You do not need the Hybrid MBR. If you have MSR/MSD, there is not Hybrid MBR on GPT-only disks. If you have Hybrid MBR, then it is a non-EFI (BIOS/Hybrid MBR) .

     

    Using Diskpart will confuse the EFI Boot and it is not a good idea.

  • by hoosentroger,

    hoosentroger hoosentroger Sep 21, 2015 9:15 AM in response to Loner T
    Level 1 (0 points)
    Sep 21, 2015 9:15 AM in response to Loner T

    I know I don't need the hybrid MBR, the reason i showed you that its protective MBR, using GPT, was to prove that it should work with the efi installation of windows 10, but it doesn't. So what might be the problem? How should I prepare the partitions, because none of the "windows 8 for mac in efi mode" tutorials work for my system. So you say I shouldn't use diskpart  but even the tutorial in this feed suggests the windows prompt, which starts with diskpart:

     

    "3.  Start Windows 8 setup in EFI mode; - switch to "Windows prompt" under "repair tools". Start command diskpart. Check your partition; - select that one with name "EFI". Add the drive letter "b" with the command assign letter=b. (Note, this point is perhaps not needed at some systems.)"

    Or Do I get it wrong?

  • by Loner T,

    Loner T Loner T Sep 21, 2015 9:18 AM in response to hoosentroger
    Level 7 (24,307 points)
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    Sep 21, 2015 9:18 AM in response to hoosentroger

    1. Remove the current GPT4 and 5.

    2. Run DU and Repair Disk. You can also boot in Safe Mode and boot normally and continue.

    3. Run SMC Reset and NVRAM Reset.

    4. Create a Free Space partition of the size you want Windows to be (+128MB for MSR). Do not use Diskpart for any drive  letter assignments.

    5. Run W10 installer and point to this Free Space.

    6. The EFI Partition should automatically get a Microsoft Directory and appropriate BD structures  during the installation using EFI Boot.

     

    I have done this on several Late 2013 and 2014 models without any issues.

  • by hoosentroger,

    hoosentroger hoosentroger Sep 21, 2015 12:55 PM in response to Loner T
    Level 1 (0 points)
    Sep 21, 2015 12:55 PM in response to Loner T

    Well, I followed your steps (except for the 128mb msr partition) tried different usb installers(ntfs, fat32, home, pro, activated versions of windows 10 64bit) and i get the same error at the end

    "windows couldn't prepare the computer to boot into the next phase of the installation"

    maybe i'll try it with a windows 8 installer, but i feel there might be some corruption issue with my efi partition or i don't know. There was also an efi security update installed on it from the app store that came out like one and a half month ago, back then it ran mavericks.

    I don't know if that 128mb msr is crucial, but when windows installer creates the primary partition it makes a 16mb msr reserved.

    any ideas? Is it possible to downgrade that efi update?


    alright this must be my problem:

    Mac EFI Security Update 2015-001

  • by Loner T,

    Loner T Loner T Sep 21, 2015 2:24 PM in response to hoosentroger
    Level 7 (24,307 points)
    Safari
    Sep 21, 2015 2:24 PM in response to hoosentroger

    I have the same EFI Update. My suggestion is to backup OS X using Time Machine, boot into Internet Recovery, erase your internal drive, restore from Time Machine and repeat the steps.

  • by TrashTreasury,

    TrashTreasury TrashTreasury Oct 3, 2015 3:50 PM in response to lion10
    Level 1 (0 points)
    Oct 3, 2015 3:50 PM in response to lion10

    Brilliant guide. I am trying this on my Mid-2012 rMBP 15" (10,1) with Windows 10. I have an Nvidia GT650M GPU and am indeed having driver problems and had to boot into Safe mode. It seems that using the default microsoft drivers does not allow you to use an external display. I found another post that said some people had sucess with earlier Nvidia drivers. I almost always use my macbook with an external display and so this would be a deal breaker for me. However having the additional speed on the SSD has been great. Has anyone solved this Nvidia driver black screen problem or have any suggestions?

    Thanks!

  • by CptWaster,

    CptWaster CptWaster Oct 5, 2015 3:32 PM in response to TrashTreasury
    Level 1 (0 points)
    Oct 5, 2015 3:32 PM in response to TrashTreasury

    Thank you for this guide. Though I had to do some additional steps to get Windows 8.1 (and eventually Windows 10) working.

    The setup stopped after I selected the partition I wanted to install to. It went to the next screen (with the next steps and progress in percent) and then showed the dreaded "Windows could not prepare the computer to boot into the next phase of installation" message.

    Seems the error shows up, because of the PCI SSD-Part of my iMacs Fusion drive.

    Here are my Steps:

    -     Backup MacOs

    -     Prepare USB-Stick with Bootcamp Assistant and prepare the Windows partition

    -     In Windows Setup (partition selection) press shift+F10 to access the console

    DISKPART

    SELECT DISK 0

    Attention! This will erase the SSD!

    CLEAN

    CONVERT GPT

    Even if we don't want to install windows onto the SSD we have to create a partition else Windows will write and install to the SSD.

    It is important that you leave some space on the SSD after the partition. It seems that Windows setup temporarily writes some stuff into this space. My SSD is 120GB.

    CREATE PARTITION PRIMARY SIZE=113000

    EXIT

    Back to the partition selection screen you can now select the partition Bootcamp created for you on the second disk and format it to NTFS.

    Click next and Windows should finally install now.

    After windows is done installing. You have to recreate your Fusion-Drive and restore (or reinstall) MacOs.

    Boot into the MacOs recovery system and open the terminal

    You have to delete the remainder of the old Fusion-Drive

    diskutil cs list

    (Copy the ID of the Volume Group)

    diskutil cs delete CopiedID

    (Clear SSD, Windows doesn't seem to need anything here)

    diskutil erase disk free space disk0

    (Create Fusion Drive)

    diskutil cs create Fusion disk0 disk1s2

    (Copy the new ID and create the volume on the Fusion-Drive)

    diskutil cs createVolume NewId JHFS+ "Macintosh HD" g0

     

    Now restore (or reinstall) MacOs.

     

    I have no idea why I have to do all these steps now. Early 2014 I just had to install it with Bootcamp-Assistant alone. Now I had to jump through several hoops and waste several days to find out these steps. Back then it was pre Yosemite, maybe the old Version of the Bootcamp-Assistant did this stuff to the SSD automatically.

     

    Hope this helps.

  • by KevinHM,

    KevinHM KevinHM Jan 19, 2016 1:35 AM in response to lion10
    Level 1 (0 points)
    Jan 19, 2016 1:35 AM in response to lion10

    Can u show diskutil list after you installed windows?

  • by jsbrock,

    jsbrock jsbrock Jun 7, 2016 9:09 AM in response to lion10
    Level 1 (4 points)
    Jun 7, 2016 9:09 AM in response to lion10

    Is it ok to use Boot Camp Assistant to Create the Windows Installer? or Just for the drivers? I don't seem to have any other options other than using a windows computer to make the installer.

  • by Loner T,

    Loner T Loner T Jun 12, 2016 6:18 PM in response to jsbrock
    Level 7 (24,307 points)
    Safari
    Jun 12, 2016 6:18 PM in response to jsbrock

    Creating an installer via USB is the safest method. What year/model is your Mac?

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