A solution that works for Windows 8.1 on MBP Late 2013

I managed to install it twice but its hit or miss (more on miss 😠)..I did everything on this thread...so just for fun I repeat the process that worked, the next time around it did not work...89-91% unexpected error...This is why some people say it worked for them its because you got lucky...

Update:I even tried wiping out the whole SSD drive and created a small partition just for windows install..the same issue..

-Tried wiping out the partition and format it exFAT , this works after 6 tries..but not anymore
- I tried copying the ISO content to the WININST EFI drive and no go..
-I tried booting to a recovery USB so I can wipe out the whole disk, repaired it and verified..no go

I tried so many times and only 2 success out of 20..

I can replicate this now..the bootcamp 5.1.64x maybe the culprit..If I move that out of the root of the EFI boot drive and it install after..If I put that back, "Unexpected Error" @89%

I did like your guideline. However, it was occured again with this error 😟 What should I do?

I installed same like you but used NTFS system in disk utility......All working fine, but sound is not working..

Macbook pro (mid 2012)

I have the same Problem as Julien,

tried every step so far and went smooth through it until i start the windows installer via the EFI Mode and want to install the system to the partition. I format the ExFat Partition, which i have created with the disk utiliy, but i keep getting the same error as before. Has somebody a solution for me. Is there a other way to format the partition to NTFS?

Just wanted to confirm that the suggestions of manually copying the contents of the Windows ISO to the USB stick worked for me, after the standard Boot Camp steps had failed for me several times on my Early 2015 MacBook Air. Just to be clear, the exact sequence of events was (after some failed attempts):

1. I opened Boot Camp Assistant (BCA), getting the option to remove the Windows 8 partition, and went through with that and got back my single-partition drive with only OS X, then I quit BCA.

2. I mounted the Windows ISO file by double-clicking it, and I opened the thumb drive and compared the folders that were present. I trashed any items at the root level of the thumb drive which were also in the Windows disk image (thus leaving on the thumb drive anything placed there by Boot Camp), emptied the trash, then selected and dragged all the items in the Windows disk image to the USB stick.

3. About half an hour later, when this operation finished, I "ejected" the Windows ISO so that only the thumb drive was still mounted, opened BCA again, and unchecked the first two options: (a) to create a bootable thumb drive, and (b) to download the "Windows support software" (the Boot Camp drivers which were still on the thumb drive from last time). This left the option to partition the drive for Windows 8 as the sole checked item.

4. When BCA finished the partition it immediately rebooted, then Windows 8 Setup started from the thumb drive as usual. This time, instead of dying at 90%, it worked! After Windows 8 had finished setting itself up, Boot Camp automatically kicked in and installed the needed drivers.

Hello !

One tip for people having problems with WINDOWS 8.1 error 0xC0000005 (stucking in 89% installation progress)

The only way for me to work was creating the bootable USB with the ORIGINAL Microsoft tool to create Windows 7/8/8.1 Bootable USB.
The Bootcamp option to create the ISO never worked for me (i have 2 Macpro Retina....15" 2013 and a 13" 20158.1

1) So i created this USB Windows 8.1
2) in Bootcamp menu i checked the option to put the drivers into it (but not create the USB bootable)
3) Installs 100% fine