lion10
Level 1 (0 points)

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

Close
lion10

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

  • All replies
  • Helpful answers

Page 1 of 4 last Next

  • by lion10,

    lion10 lion10 May 4, 2014 7:47 AM in response to lion10
    Level 1 (0 points)
    May 4, 2014 7:47 AM in response to lion10

    Addendum, 4. May 2014

     

     

    Although iMac with year 2007 & 2008 are 64bit EFI based, it is NOT possible to install Windows 8 in EFI mode. The reason is that those iMac use EFI 1.x based firmware. As a result, the Windows 8 EFI installer freezes immediately at startup.


    2009 and later iMac systems seem to be mostly (U)EFI 2.x based, - the Windows 8 installer loads fine at startup.

  • by Ted Lambert,

    Ted Lambert Ted Lambert May 4, 2014 9:53 AM in response to lion10
    Level 1 (0 points)
    May 4, 2014 9:53 AM in response to lion10

    Is this easy as i'm not real good with the terminal and fdisk. If you could give a step by step I would be greatful!! Ted

  • by lion10,

    lion10 lion10 May 4, 2014 12:34 PM in response to Ted Lambert
    Level 1 (0 points)
    May 4, 2014 12:34 PM in response to Ted Lambert

    Hi Ted, - you see the four steps above. If it's still to complicated, use Boot Camp instead. That also works and is good enough for most. However, one disadvantage is that you will not have under Windows some functions like AHCI enabled SATA controller etc.

  • by yujyufudan,

    yujyufudan yujyufudan Aug 7, 2014 9:52 PM in response to lion10
    Level 1 (0 points)
    Aug 7, 2014 9:52 PM in response to lion10

    Today I followed this recipe exactly to add Windows 8.1 to a 13 inch Retina, Late 2013.  My reason for wanting to go this route and keep the disk purely GPT was in order to have three visible partitions: one OSX, one Windows, and one exFat Data.

     

    Windows installed flawlessly with zero fuss.  I've restarted the system several times in both operating systems and made various updates.  Everything is going fine so far, and I can access all three partitions from either OS.

     

    It might be worth mentioning that I created a USB Windows boot disk using method 3 provided here:

    http://tipsandtricksforum.com/thread-245.html

    I then added the boot camp drivers by downloading and following the directions here:

    Boot Camp Support Software 5.1.5640

    I guaranteed that the Windows boot disk would only boot in EFI mode by following the directions here:

    http://technet.microsoft.com/en-us/library/dn293283.aspx

     

    Once I began installing Windows, I had to format the partition I'd created for it.  (I had just made it exFat for the time being when I created it in Disk Utility.)  Other than that, it was a completely straightforward, out of the box Windows install.  (No need to hold down the alt key on reboots, or any of that.)  Once the installation was finished, I ran Setup from the Boot Camp folder on my USB boot disk to get all my drivers in place.

     

    I noticed that running setup for the boot camp drivers changed the name of my Windows partition to BOOTCAMP.  I was afraid it might have messed with my MBR as well.  I checked with gdisk, and confirmed that the disk is still GPT with protective MBR. -- For anyone wondering what all that mumbo-jumbo means, it's what you need in order to have more partitions than just Macintosh HD and BOOTCAMP.

     

    Awesome.  Thanks lion10.

  • by PliSsK,

    PliSsK PliSsK May 9, 2015 9:51 AM in response to lion10
    Level 1 (0 points)
    May 9, 2015 9:51 AM in response to lion10

    Is there another option to boot up Windows 8.1 (x86 or x64) installation media on EFI 1.1 Macs?

  • by Loner T,

    Loner T Loner T May 9, 2015 11:36 AM in response to PliSsK
    Level 7 (24,098 points)
    Safari
    May 9, 2015 11:36 AM in response to PliSsK

    You only have two methods, EFI (which does not work correctly on Macs prior to Late 2013 models) or BIOS (aka Hybrid MBR) on older Macs. Virtualization engines provide a different path without partitioning.

  • by PliSsK,

    PliSsK PliSsK May 10, 2015 9:45 AM in response to Loner T
    Level 1 (0 points)
    May 10, 2015 9:45 AM in response to Loner T

    Thanks for your input!

     

    BTW Is there any way to modify the contents of the Win 8.1 installer ISO so that it boots up in EFI 1.1 or BIOS so it can used to install Windows on an early 2008 8,1 iMac or earlier?

     

    I have tried a number of different things and so far the only thing that has worked is to install Win 8.1 x64 in a VM. I was really wanting to install it in a partition, to maximise performance. Unless I can modify the Win 8.1 installer then my only other option (besides using a VM) is to use bootcamp to create a Windows 7 x86 partition (or possibly an x64 partition if I can fool bootcamp) and run the relevant x86 or x64 Win 8 installer from within Win 7.

  • by nuwanfromsg,

    nuwanfromsg nuwanfromsg May 23, 2015 2:50 AM in response to lion10
    Level 1 (0 points)
    May 23, 2015 2:50 AM in response to lion10

    Hi lion10 / yujyufudan,

     

    Once install Windows this way how to switch between them ? Is it by pressing Option key at bootup ?


  • by T0m93,

    T0m93 T0m93 May 23, 2015 3:30 AM in response to lion10
    Level 1 (0 points)
    May 23, 2015 3:30 AM in response to lion10

    Hey i dont get step 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.)"


    how do i switch to Windows prompt? Do i have to press something when booting the usb Stick? i can just see install :/

  • by Loner T,

    Loner T Loner T May 23, 2015 5:05 AM in response to T0m93
    Level 7 (24,098 points)
    Safari
    May 23, 2015 5:05 AM in response to T0m93

    T0m93 wrote:

     

    Hey i dont get step 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.)"


    how do i switch to Windows prompt? Do i have to press something when booting the usb Stick? i can just see install :/

    You need to run Windows Installer in EFI Mode and then click on Repair once the installer starts. One option in Repair Tools is Windows prompt (aka command prompt). On older Macs this can cause your GPU, Audio to not function properly.

  • by T0m93,

    T0m93 T0m93 May 23, 2015 5:13 AM in response to Loner T
    Level 1 (0 points)
    May 23, 2015 5:13 AM in response to Loner T

    Well it worked with shift f10. And some how i Managed to Type in the right commands and Assisi efi=b, but when i tried to install win 8.1 it says: i should convert the EFI drive from nfts into fat32. I dont really know What to do Anybody had this before? (MB pro late 2011 with fusiondrive)

  • by Loner T,

    Loner T Loner T May 23, 2015 7:07 AM in response to T0m93
    Level 7 (24,098 points)
    Safari
    May 23, 2015 7:07 AM in response to T0m93

    EFI installation require a MSR (Microsoft Reserved) and a separate NTFS (MSD) partition. Typically the partition is formatted as a Free Space, which allows the EFI Installer to carve out a 128MB MSR and the remainder goes to the NTFS partition.

  • by T0m93,

    T0m93 T0m93 May 24, 2015 12:57 PM in response to Loner T
    Level 1 (0 points)
    May 24, 2015 12:57 PM in response to Loner T

    Ok. Hmm does anyone know how i can convert a Partition into free Space. I got Fusion Drive and cant delete it (Partition is from SSD not from the Fusion Drive). Is there any Terminal command?

    And the win8 setup created around 6 new 100-300MB Partitions by now. Does anyone know how i can get them all back together? Hopefully i will get this to work some how

  • by Loner T,

    Loner T Loner T May 24, 2015 1:41 PM in response to T0m93
    Level 7 (24,098 points)
    Safari
    May 24, 2015 1:41 PM in response to T0m93

    Please post the output of

     

    diskutil cs list

    sudo gpt -vv -r show /dev/disk0

    sudo gpt -vv -r show /dev/disk1

     

    Every failed attempt at EFI install creates an MSR and fails, leaving the MSR hanging.

Page 1 of 4 last Next