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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

Best reply

Loner T

Level 9

59,477 points

Posted on Nov 14, 2014 9:13 AM

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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95 replies

Sep 17, 2015 12:35 PM in response to Loner T

"Can you post the output of the GPT and Fdisk commands so we can verify it?"

How can I do that ?

If it can help you :

Informations matériel :

Nom du modèle : MacBook Pro

Identifiant du modèle : MacBookPro8,1

Nom du processeur : Intel Core i5

Vitesse du processeur : 2,3 GHz

Nombre de processeurs : 1

Nombre total de cœurs : 2

Cache de niveau 2 (par cœur) : 256 Ko

Cache de niveau 3 : 3 Mo

Mémoire : 4 Go

Version de la ROM de démarrage : MBP81.0047.B2A

Version SMC (système) : 1.68f99

Capteur de mouvement brusque :

État : Activé

So, I work hard since 8 days to install Windows on my OptiBay Mac... I understand that with my Mac, it's impossible to install Windows on EFI boot... But, this is the only way I have at the boot. I don't have "WINDOWS" and "WINDOWS EFI", just the second one... I try to find a solution to have this "WINDOWS", and make an install in MBR, with the BIOS.... I'm on different forums, apparently this is the only way possible, what do you think about that ?

The problem I have is with the bootable USB drive, I think... With "Rufus" sofware, on Pc, I can create a bootable USB drive with this option : http://img11.hostingpics.net/pics/681836image730.jpg (MBR Partition to BIOS or UEFI) but the USB drive is only on NTFS, and my Mac can't read it at the boot...

I'm 95% sure that with the MBR installation, I can install Windows...

Loner T

Level 9

59,477 points

Sep 17, 2015 12:35 PM in response to Jordan Machin

Please edit your post and remove the serial number of your Mac.

What we should look at is something similar to the following. The last two commands must be run for each disk in your Mac.

diskutil list

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 741.7 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data rMBPBCMP 258.0 GB disk0s4

sudo gpt -vv -r show /dev/disk0

Password:

gpt show: /dev/disk0: mediasize=1000555581440; sectorsize=512; blocks=1954210120

gpt show: /dev/disk0: Suspicious MBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 1954210119

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 1448624648 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

1449034288 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

1450303824 1712

1450305536 503904256 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

1954209792 295

1954210087 32 Sec GPT table

1954210119 1 Sec GPT header

sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 121643/255/63 [1954210120 sectors]

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 0 0 2 - 25 127 14 [ 1 - 409639] <Unknown ID>

2: AF 25 127 15 - 1023 54 16 [ 409640 - 1448624648] HFS+

3: AB 1023 54 17 - 1023 60 39 [1449034288 - 1269536] Darwin Boot

*4: 07 1023 87 51 - 1023 238 3 [1450305536 - 503904256] HPFS/QNX/AUX

Sep 17, 2015 12:40 PM in response to Loner T

Thx for the serial number, I want to make things too fast, I'm an idiot.

Here' my list :

Last login: Thu Sep 17 21:21:50 on ttys000

MacBook-Pro-de-Jordan:~ Jordan$ diskutil list

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *250.1 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS SSD 124.7 GB disk0s2

3: Microsoft Basic Data BOOTCAMP 125.0 GB disk0s3

/dev/disk1

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *500.1 GB disk1

1: EFI EFI 209.7 MB disk1s1

2: Apple_HFS HDD 499.8 GB disk1s2

MacBook-Pro-de-Jordan:~ Jordan$ sudo gpt -vv -r show /dev/disk0

Password:

gpt show: /dev/disk0: mediasize=250059350016; sectorsize=512; blocks=488397168

gpt show: /dev/disk0: Suspicious MBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 488397167

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 243584720 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

243994360 262408

244256768 244140032 3 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

488396800 335

488397135 32 Sec GPT table

488397167 1 Sec GPT header

MacBook-Pro-de-Jordan:~ Jordan$ sudo gpt -vv -r show /dev/disk1

gpt show: /dev/disk1: mediasize=500107862016; sectorsize=512; blocks=976773168

gpt show: /dev/disk1: PMBR at sector 0

gpt show: /dev/disk1: Pri GPT at sector 1

gpt show: /dev/disk1: Sec GPT at sector 976773167

start size index contents

0 1 PMBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 976101344 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

976510984 262151

976773135 32 Sec GPT table

976773167 1 Sec GPT header

MacBook-Pro-de-Jordan:~ Jordan$

Loner T

Level 9

59,477 points

Sep 17, 2015 12:42 PM in response to Jordan Machin

Can you post the Fdisk output for both disks?

Sep 17, 2015 12:47 PM in response to Loner T

I think it's good :

MacBook-Pro-de-Jordan:~ Jordan$ diskutil list

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *250.1 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS SSD 124.7 GB disk0s2

3: Microsoft Basic Data BOOTCAMP 125.0 GB disk0s3

/dev/disk1

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *500.1 GB disk1

1: EFI EFI 209.7 MB disk1s1

2: Apple_HFS HDD 499.8 GB disk1s2

MacBook-Pro-de-Jordan:~ Jordan$ sudo gpt -vv -r show /dev/disk0

Password:

gpt show: /dev/disk0: mediasize=250059350016; sectorsize=512; blocks=488397168

gpt show: /dev/disk0: Suspicious MBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 488397167

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 243584720 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

243994360 262408

244256768 244140032 3 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

488396800 335

488397135 32 Sec GPT table

488397167 1 Sec GPT header

MacBook-Pro-de-Jordan:~ Jordan$ sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 30401/255/63 [488397168 sectors]

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>

2: AF 1023 254 63 - 1023 254 63 [ 409640 - 243584720] HFS+

3: 0B 1023 254 63 - 1023 254 63 [ 244256768 - 244140032] Win95 FAT-32

4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

MacBook-Pro-de-Jordan:~ Jordan$ sudo gpt -vv -r show /dev/disk1

gpt show: /dev/disk1: mediasize=500107862016; sectorsize=512; blocks=976773168

gpt show: /dev/disk1: PMBR at sector 0

gpt show: /dev/disk1: Pri GPT at sector 1

gpt show: /dev/disk1: Sec GPT at sector 976773167

start size index contents

0 1 PMBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 976101344 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

976510984 262151

976773135 32 Sec GPT table

976773167 1 Sec GPT header

MacBook-Pro-de-Jordan:~ Jordan$ sudo fdisk /dev/disk1

Disk: /dev/disk1 geometry: 60801/255/63 [976773168 sectors]

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 1023 254 63 - 1023 254 63 [ 1 - 976773167] <Unknown ID>

2: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

3: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

MacBook-Pro-de-Jordan:~ Jordan$

Loner T

Level 9

59,477 points

Sep 17, 2015 1:41 PM in response to Jordan Machin

Jordan Machin wrote:

MacBook-Pro-de-Jordan:~ Jordan$ sudo gpt -vv -r show /dev/disk0

Password:

gpt show: /dev/disk0: mediasize=250059350016; sectorsize=512; blocks=488397168

gpt show: /dev/disk0: Suspicious MBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 488397167

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 243584720 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

243994360 262408

244256768 244140032 3 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

488396800 335

488397135 32 Sec GPT table

488397167 1 Sec GPT header

MacBook-Pro-de-Jordan:~ Jordan$ sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 30401/255/63 [488397168 sectors]

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>

2: AF 1023 254 63 - 1023 254 63 [ 409640 - 243584720] HFS+

3: 0B 1023 254 63 - 1023 254 63 [ 244256768 - 244140032] Win95 FAT-32

4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused

The highlighted entries match. If you connect the External Optical drive and boot from it, can the Windows installer see disk0 Partition 3 as a valid destination for installation?

Sep 17, 2015 1:46 PM in response to Loner T

When I boot from my external optical drive, with the official Windows 7 DVD, I have the black screen with "_" in the corner...

Sep 17, 2015 2:13 PM in response to Jordan Machin

I did a test... When my external optic drive and my usb flash with the windows bootcamp drivers are plug in, when I select "WINDOWS" at the boot, I have the message : "Couldn't find Bootmgr"... Is it a joke ?

And when I boot on "EFI Boot", I'm going to OS X.... please

Loner T

Level 9

59,477 points

Sep 17, 2015 2:16 PM in response to Jordan Machin

Remove the USB, boot from the external Optical drive and choose Windows (not EFI Boot). What do you see?

Sep 17, 2015 2:19 PM in response to Loner T

Nothing, just a black screen with "_" like I said. It's something like that : http://oi50.tinypic.com/wk5rwm.jpg and the "_" is flashing

Sep 17, 2015 2:27 PM in response to Jordan Machin

Do you think that's because my Windows 7 is an OEM version ?

Loner T

Level 9

59,477 points

Sep 17, 2015 2:29 PM in response to Jordan Machin

Your OEM disk will usually be a full OS Restore disk, not an installer. Can you get access to a retail W7 Installation DVD?

Sep 17, 2015 2:53 PM in response to Loner T

****... I believed it was possible... Right now I just have this DVD, but I have an official Windows 8.1 ISO... I'll searching for a blank DVD, you think it will works if I burn my ISO into it ?

I'd like to tell you my problem again, when I try to install Windows with a USB drive :

1. Windows tells me that it need a GPT partition, not an MBR : fixed ! With that http://superuser.com/questions/508026/windows-detects-gpt-disk-as-mbr-in-efi-boo t

2. I had some problem for the partition that Windows needs to its "BIOS emulator" : fixed

3. http://img11.hostingpics.net/pics/584324image126.jpg Windows says that the EFI partition (for him, I think so) is on NTFS, needs to be in FAT32... And it's in FAT32, but doesn't work even though...

A dude tells me that on my MacBook Pro early 2011 with OptiBay, it's impossible to install Windows in EFI... I'm really searching for a way to have this MBR install icon.... With the bootable USB drive... I know I'm close to the truth, but I need help

PS : What if I change that ??

<key>PreUEFIModels</key>

<array>

<string>MacBook7</string>

<string>MacBookAir5</string>

<string>MacBookPro10</string>

<string>MacPro5</string>

<string>Macmini6</string>

Loner T

Level 9

59,477 points

Sep 17, 2015 3:15 PM in response to Jordan Machin

It will cause issues with GPU and Sound drivers, in the least. There may also be issues with other drivers.

Sep 17, 2015 3:07 PM in response to Loner T

Even with the Bootcamp drivers ?

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