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:
Step 2: It asks me to locate and select the ISO file of Windows 8.1 which I downloaded from Microsoft website.
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)
Step 4: I see that downloading is completed and installation has begun.
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)
Step 6: I see that disk partitioning has begun
Step 7: I get an error in boot camp which reads: Disk cannot be partitioned.
Step 8: Now, I check disk utility once again to see if any changes are there:
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:
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.
Best Answer
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.