Convert flash drive for Windows 8.1 bootcamp installation from mbr to gpt

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Convert flash drive for Windows 8.1 bootcamp installation from mbr to gpt

Trying to run Windows 8.1 pro x64 on my mid 2010 15" macbook pro. Get stuck during bootcamp installation in Windows because my partition table isn't compatible (MBR but needs to be GPT). My hard drive seems to be Logical partitions/volume etc, while my flash drive was formatted into MBR seemingly by bootcamp, or otherwise not altered into the GPT like it maybe should have.

Generally followed this guide http://www.howtogeek.com/186907/how-to-install-windows-on-a-mac-with-boot-camp/

Steps I took:

Had to use terminal/Xcode to edit info.plist from bootcamp to allow flash drive installation through bootcamp on my mac (removed the "pre" method).

With all three bootcamp options selected, managed to partition the drive

When restarted, my computer had black screen with "no bootable device found".

Restarted again, holding alt/option

Flash drive was now available as one of two options (the other being my standard mac drive)

Windows Setup loaded. Selected language/imputed key/select version etc.

Here is the strange part, the division of the disk does not include "bootcamp" anywhere in the title (like it should according to the guide), and is about 10gb smaller than my partition (assume this is a normal result of windows installation/os files etc). When I try to format the partition, it says I can't, and explains that I can't use MBR, need to use GPT.

Attempted to rewrite disk with Shift F10 Diskpart, list disk, etc, but here it shows drive 0, 1, and 2, (rather than drive 0 partition 1,2,3,4, with 4 being my bootcamp I think). This seems to be a method for installing windows on a windows pc, and I didn't go through with it because I didn't want to loose my mac os yet.

I am not proficient with coding/terminal use, and don't know if there is an option to list partitions etc, so I'm stuck. I can backup my mac and potentially change my partition table etc, but I feel like restoring with time machine would then wipe my existing partition. Is there a workaround I could use? Is there a specific sequence of backups/restores that would work? I'm also okay with manually drag and dropping the files I want back onto a clean slate computer if necessary. Or would simply buying and burning a disc with windows save myself the hassle? Please advise.

Sorry for long question, wanted to get info out right away. Can include more if necessary. Thank you all for your time.

MacBook Pro, OS X Yosemite (10.10), mid 2010 15" Nvidia GeForce 330

Posted on Nov 14, 2014 8:59 AM

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Answer 1

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Loner T

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Nov 14, 2014 9:13 AM in response to TheMonark

Please post the output of following

diskutil list

diskutil cs list

sudo gpt -vv -r show /dev/disk0

sudo fdisk /dev/disk0

You will need to use Terminal and input your password when prompted. You can triple click on each line and Copy (Command+C) and Paste (Command+V) into the terminal window. Remove any personal information that you do not to be seen on the discussions.

Creating a USB is only part of the problem if your built-in Optical drive is not working. The CSM-BIOS layer used still needs to be configured in the Mac Nvram to boot from USB.

If you have W8.1, which has EFI support, you can try that, but your Mac from 2010 is a preUEFI model, as shown in your Bootcamp info.plist.

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Answer 2

TheMonark Author

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Nov 14, 2014 10:41 AM in response to Loner T

Thank you for your response. Just want to clarify some things.

I input that into mac terminal while running os? And then you'd like me to post the results on this discussion board?

My optical drive works fine, but I moved to France and didn't bring any disks. Would it be easier and safer to just burn my windows iso onto a disc and run it through bootcamp that way? I'm thinking the answer is yes at this point.

I'm about to head out to celebrate a birthday, but I will post back here in about 14 hours. Do you recommend just buying a DVD and doing it that way? I could easily return my info.plist to normal, and as far as I know, my optical drive works fine. Seems simpler if it would work with my copies of osx and windows. What do you recommend?

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Answer 3

Loner T

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59,471 points

Nov 14, 2014 11:06 AM in response to TheMonark

TheMonark wrote:

I input that into mac terminal while running os? And then you'd like me to post the results on this discussion board?

Yes. It also helps if there are any calculations to be done with disk sectors.

My optical drive works fine, but I moved to France and didn't bring any disks. Would it be easier and safer to just burn my windows iso onto a disc and run it through bootcamp that way? I'm thinking the answer is yes at this point.

Yes, if you have a built-in Optical drive, Bootcamp expects to boot from the Optical drive, because it sets the CSM-BIOS layer for Windows to boot from the Optical drive settings in the NVRAM.

I'm about to head out to celebrate a birthday, but I will post back here in about 14 hours.

Enjoy the party! 😉

Do you recommend just buying a DVD and doing it that way? I could easily return my info.plist to normal, and as far as I know, my optical drive works fine. Seems simpler if it would work with my copies of osx and windows. What do you recommend?

The changes in info.plist enable creation of the USB, but do not influence the boot device pointer that BCA will set when switching to the Windows Installer. My recommendation is to get DVD writable media (DVD+R or equivalent) and burn the ISO to a physical DVD and use BCA to install windows using the BCA USB and DVD media.

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Answer 4

TheMonark Author

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Nov 15, 2014 4:17 AM in response to Loner T

My recommendation is to get DVD writable media (DVD+R or equivalent) and burn the ISO to a physical DVD and use BCA to install windows using the BCA USB and DVD media.

Wow thank you so much for all of that! I think what I'll do is grab some DVD-Rs and try the optical drive method for simplicity's sake. I know there's a right-click option to burn something to a disc, will that be sufficient? Or does the burning need to happen in BCA?

install windows using the BCA USB and DVD media.

Does this require a USB for the installation software, or can all of that be put onto the DVD?

Enjoy the party! 😉

Haha turned out to just be dinner, but was a **** good meal.

Thanks again for everything, you've been super helpful. I'll post back when I try the DVD method. Figure it should be relatively straight forward compared to what I've been attempting up til now.

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Answer 5

Loner T

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59,471 points

Nov 15, 2014 7:06 AM in response to TheMonark

Please see Disk Utility 12.x: Burn a disk image to a CD or DVD for creating a physical media. BCSA is not involved in it. The mid 2010 Macs are a bit too old for ISO based installation.

The USB is used to download the BC drivers only for machines which have a built-in Optical drive. After Windows installation is complete, the USB is used to install BC drivers, and this is supposed to be a silent install, but it does not always remain silent. These can also be manually installed.

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Answer 6

TheMonark Author

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Nov 15, 2014 9:24 AM in response to Loner T

Okay, so I have a question then. I've burned the iso to the disk. I already used the 3 check BCA to create a partition. Now that I'm going to be installing through dvd, can I insert my disk, shut off my mac, reboot with alt/option, select the disc if possible, install windows, and use the usb I've already formatted for support software?

I'm concerned that the usb is no longer useful for this purpose because the iso is imbedded somewhere in there. Is there a simple solution such as doing nothing, or deleting only a part of it where the iso is, or do I need to redo the software download through BCA?

I'm also concerned that the partition needs to be deleted and reinstalled as well. I guess what I'm asking is, now that I have a dvd with windows iso burned, how should I proceed?

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Answer 7

Loner T

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59,471 points

Nov 15, 2014 9:34 AM in response to TheMonark

If you have the USB with drivers and the DVD inserted, let BCA do it for you. You do not need to shut down or reboot.

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Answer 8

TheMonark Author

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Nov 15, 2014 9:49 AM in response to Loner T

With disc and usb inserted, I went to Bootcamp and tried to restore my mac osx, because it's the only option that seems to be available through bootcamp. It fails to restore with the message "An error occurred while restoring the disk to a single partition." I have no idea why this is. Should I try the manual booting method since I've already partitioned my drive?

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Answer 9

Loner T

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59,471 points

Nov 15, 2014 11:36 AM in response to TheMonark

The last time you attempted it, it created the partition, so you already have it. The error message you get is because removing the current (although there is no Windows on it) requires additional disk space for repartitioning, which is no longer available.

My suggestion si to insert the USB (because it has the BC drivers) and the DVD, both, and use the Alt key. The risk is that you keyboard/video/monitor may not work, because the CSM-BIOS layer is being by-passed, but it should be tried first, before a cleanup and starting all over again is attempted.

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Answer 10

Sep 9, 2015 5:17 PM in response to Loner T

Sorry for my english, I'm french...

Loner, I'm desperate... I'm on a macbook pro 2011 and I have the same problem to install w7 so I wrote your commands "

diskutil list

diskutil cs list

sudo gpt -vv -r show /dev/disk0

sudo fdisk /dev/disk0"

But, since these commands, I can't go anymore on my mac osx partition..... I don't find a command to be back by default on fdisk, I don't know what to do, can you help me please ? with a magic command.... My drive isn't deleted, but I just can't go on it

Thx