Q: Windows 8.1 install fails on new 2013 Retina MacBook

I have to aplogize, I didn't realize I was going through the BIOS method and not EFI. I've now 'learnt' myself on BIOS vs. EFI installs and will be trying a pure EFI install.

Sorry to have caused confusion! I've been a hardcore PC user for 20 years, and this MBP is actually my first Mac. I'm trying an EFI install now, but I expect issues like everyone else. I'll update with what happens, good or bad.

No worries, my next try is going to be through applying an image of my old Bootcamp to my new laptop via WinClone.

EFI install was successful on my 15" MBP! Yes, with itsy bitsy hard-to-read text during the installation. I didn't do anything special, just followed the normal Boot Camp guide.

I will add one thing that may be pertinent - the Windows 8.1 Pro ISO I used was just downloaded today with the MS installer tool, so there's a small chance the ISO was updated since the retail DVD launch, but that's entirely a hypothesis on my part.

Congrats! It's so weird that it just randomly starts working for some people. I still haven't got it to work. The WinClone option didn't pan out, I'm currently trying to do Win 7.

Still not working, but random tidbit of knowledge:

I was confused because bootcamp randomly started saying that the iso I was using was not 64bit / wasn't a valid windows ISO. I hadn't made any changes to the iso file.

I finally figured out that dragging the iso file into the file picker box doesn't work. You have to click choose file, and browse the the ISO, even though the UI seems to respond positively to you dragging the ISO file. Once I chose the file manually, it let me copy the iso to my usb drive as normal.

Ok, I've successfully got 8.1 installed, via the Windows 7 -> Windows 8.1 route. The "hanging" on 65% during the 7 install that I previously mentioned was, as others said, just it taking a long time. I waited it out and it continued. I'm not sure if that means I'm booting with BIOS now?

Nevertheless though, it's installed. So that's something at least. Getting drivers now, will post again if I encounter problems with this route.

EFI Installation succeded without any problems after changing the windows 8.1 version!

It works with the windows 8.1 gb-en version. It does not work with the normal english version.

steps:

(- undo all changes done by bootcamp)

- use bootcamp to create a windows usb stick (use united kingdom english iso, select only the two upper options in bootcamp tool)

- resize your osx partition using osx Disk Utility

- restart and press option key

- select efi boot

- use windows installer to create new partitions in the unallocated space (e.g. a windows and a data partition)

- install windows

- during installation the system will reboot 2 or 3 times, press the option key while restarting and select the windows hard disk symbol (not the usb stick!)

- The "getting things ready" dialog takes its time... up to 10 minutes on the top model of the rMBP 15" late 2013, so be patient!

So you say the 8.1 english gb version installs which is rather weird but ok, could you tell me where you can get this version from?

Oh I contacted Apple a few days ago and they said they are aware of the problem and are working with Microsoft to resolve it.

I got mine via MSDN subscription, but according to Shodan_Cat a fresh download of the normal iso via MS installer tool should work too.

I've managed to get WIndows 8.1 installed via the sugested Windows 7 to Windows 8.1 route ( thanks for the help ). 

However I'm getting issues when trying setup a Windows7 HyperV machine.  When I try to start it I get the following screen:

Has anyone managed to fix this, or can use Hyper-V without issue?

Hmm. I have the GB Win 8.1 ISO (full install) and it didn't work for me.

Given that some people have the problem and some don't either@

people aren't doing it exactly the same way each time

or

some people have faulty machines.

What I do know is that if you use DiskUtility to format a partition as FAT, it creates a hybrid-MBR disk, which isn't compatible with EFI booting.

But so far, when I try and do an EFI install (following the instructions above of selecting the first 2 options in BootCamp Assistant, then creating the partition manually in DiskUtility), I always get to the end of the Win 8.1 install with the error that Win8.1 can't update the boot configuration. If you look at the setup log files, you can see it's a BCD error - the Win 8.1 installer can't create BCD entries.

And when I mount the EFI partition from the installer and try myself, I also an't modify entries.

So I think it's some weird interaction between the Win 8.1 installer and the EFI partition.

One poster in anothe forum thought it might be a SecureBoot issue - I hope not, I don't want to think that Apple would go down the route of limiting what you'd be able to install on their hardware!

So, just for kicks, I followed the guide here:

http://blog.thedeltaflyer.com/2013/01/dual-booting-windows-8-and-mountain-lion-n atively-using-efi/

on booting from EFI on a rMBP.

What's different, is that the guide has you remove everything on your HDD and rebuild the EFI partition using windows Diskpart tool. I wondered whether the fact that the EFI partition was created by OSX was the root cause of the problems.

But alas, no. Win 8.1 still failed with the exact same error about being unable to set boot configuration.

I managed to fix that (by manually creating the BCD file again) but then again, windows fails at the end of the install with the same old error about being unable to finish configuring.

What've discovered is that the last error (right at the end of setup) is when sysprep is running, and it's attempting to update the BCD.

So it looks like there is something with regards to the Apple EFI (or the EFI partition) that the windows installer doesn't like.

I can get Windows up and running via msoobe, but it's in Sysprep Audit mode and a number of things don't work.

So now I'm going to ry a vanilla BootCamp install - but since BootCamp only supports 1 windows partition, I'll need to use HyperV for everything else (or see if rEFInd will work).

Sigh.

OK, so I decided to try the vanilla BootCamp approach: reinstalled OSX on a blank HDD (i.e. erased the entire SSD).

I then used BootCamp Assistant and selected all 3 options.

After reboot, in the Windows Installer I selected the new windows partition, deleted it, and created a smaller one.

And then.. I get the same error again:

Windows could not update the computer's boot configuration.

Installation cannot proceed.

Currently on hold with AppleCare support (Australia).

She has basically told me that this is a Microsoft problem and I'd need to contact them for support - i.e. because BootCamp has done it's job and got me into the installer, there's nothing they can do.

She has suggested I contact Microsoft for support.

OK, so I can get it to work, if I follow instructions found earlier in this forum, and delete the BootCamp Assistant created BOOTCAMP partition and recreate it using DiskUtility (formatted as exFAT).

I can see why this works: it cerates a hybrid-MBR disk, and so Windows installs via BIOS mode.

So it looks like by default BootCamp Assistant creates a GPT partition for Windows, which causes Windows Installer to run in EFI mode.

So if you don't force Windows Installer to use BIOS mode, the install fails.

But if you can install Windows in EFI mode on a MBA 13', surely it should work on a rMBP 15.

But the problem is either that:

a) BootCamp Assistant creates a GPT partition by default when it should create a hybrid-MBR one

OR

b) There is something up with the Mac EFI that prevents Windows from writing BCD info to it.

Ah well.

BIOS loading it is.

First impressions: slow. And I hate the fact that the installer/load screens aren't at full resolution!

Still, l'll take working slow loading windows over no windows!

I don't think it's an EFI problem, because I was able to install it. A GPT partition is required for EFI installs. The hybrid MBR/GPT partition is required for the BIOS emulation method. Boot Camp creates a GPT partition so Windows will install in EFI by default.

Still, at least you got it working for now. As I mentioned earlier, I did the BIOS method first and it worked pretty well actually. The only downsides I could see were increased boot and wake-from-sleep times.

Have you considered trying to download the latest ISO with the MS installer tool? It's the only thing I can think of that I've done differently from most that allowed me to run the EFI install.