I've MacBook Pro Retina, 15-inch Mid 2015 having 250GB SSD storage.

I'm trying to install Windows 8.1 (which my MacBook supports as per Apple's Documentation for BootCamp) but not able to do so, in a while.

It looks like my MacBook is on Apple's new file system that is APFS and windows support drivers are not supported yet. (Or I do not know if they support it)

If anyone knows how to do it on a System having APFS, please let me know.

Here's the update on error screens and what I'm seeing:

Step 1: Launch the Boot Camp Assistant and I see this:

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Step 2: It asks me to locate and select the ISO file of Windows 8.1 which I downloaded from Microsoft website.

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Step 3: I see that it started downloading the Microsoft Support software. Also, I observe that a 4.2 GB of unknown format disk is created in disk utility. (Which I suppose, is a placeholder for the currently downloading Windows support software since Apple says, my MacBook version do not need any external bootable thumb drive)

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Step 4: I see that downloading is completed and installation has begun.

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Step 5: I check the disk utility once again to see available partitions. (To make sure if boot camp is doing partition in next step or not)

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Step 6: I see that disk partitioning has begun

enter image description here Thanks in advance.

Step 7: I get an error in boot camp which reads: Disk cannot be partitioned.

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Step 8: Now, I check disk utility once again to see if any changes are there:

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I see that two partitions named as OSXRESERVED and BOOTCAMP are created but they are unmounted by default.

Step 9: I try to rerun the boot camp assistant to try my luck and I get the following error:

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Read the error description: It reads as my Macbook's startup disk should be formatted as Mac OS Extended (Journaled). But, my MacBook is having APFS which is different from Mac OS Extended (Journaled).

Any proper help is much appreciated.

2 Answers 2


Use bootcamp assistant to partition the SSD, then install windows on the new windows-supported partition.

Alternatively boot into recovery mode, use disk utility to delete the existing partition (this will wipe everything, if you have anything you need on the Macbook's SSD back it up first), then install windows and let the windows installer partition the SSD.

  • 1
    I'm confused here! Please elaborate what do you mean by Use BootCamp Assistant to partition SSD? How it matters when my problem is with Apple File System and not with partitioning? I'm able to partition the SSD but it says, some error witht he disk partitions, check in Disk Utility. Jun 17, 2018 at 6:23
  • 2
    If you're trying to dual boot, try following the instructions at this apple KB support.apple.com/en-au/HT201468 . If you still have an error after that please update your question with the error. If you don't want to dual boot and are happy to wipe everything currently on the mac you can delete the existing partitions and install windows, allowing windows to create its own partition.
    – Scottmeup
    Jun 17, 2018 at 16:03
  • I've updated the questions with screenshots. Any idea about this? Jun 27, 2018 at 6:18

If you have already created your bootable Windows 8.1 install USB thumb drive you should be able to just follow the prompts inside the Boot Camp application.

After you create the Windows installer the Mac will reboot and give you a dialog box that allows you to allocate the amount of space you want to dedicate to Windows. Just slide the handle in the middle left or right until you have the desired space configuration.

You should not have to concern yourself with the file system the Mac side is using as Boot Camp will format that part of this disk specifically for windows.

  • 2
    Why should I create bootable windows 8.1 usb? My Mac supports without USB drive. SO, I do not get an option to create bootable media in boot camp. It directly downloads the windows support softwares Jun 17, 2018 at 20:00
  • 2
    @VighneshPai That’s really irrelevant but probably correct. I’d focus on making the correct partition so you’re writing windows to a non APFS filesystem. It uses GPT for the partition scheme so you should have no issued with APFS being present as opposed to HFS+ for data that’s outside the BootCamp jurisdiction.
    – bmike
    Jun 17, 2018 at 22:10
  • @bmike I've updated the question with screenshots on what I'm doing and what is being shown to me. Please help me understand if I'm doing anything wrong. Jun 19, 2018 at 6:53

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