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MBR partition table, only GPT disk

Last week or so, I posted a thread about my MacBook having no DVD drive. It is MBP 13" Early 2011.


I was able to boot from external DVD drive (my original DVD drive is no good) and USB to install Windows 8.1.


The error message I have while before installing Windows 8.1 was as follows: WIndows cannot be nstalled on this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed on GPT disks.


My main harddrive is a SSD, Samsung SSD 850 PRO 256GB. Do I have to reformat the whole thing and make sure it doesn't format as MBR? I think this is no brainer, based on what I've researched. I just need confirmation. I'm still struggling to install Windows and it has been exhausting. The error message was the exact same when I was able to burn Windows 8.1 ISO to DVD and boot from DVD.


Any help will be greatly appreciated. Thanks.

MacBook Pro (13-inch Early 2011), OS X El Capitan (10.11.3)

Posted on Apr 3, 2016 8:15 PM

Reply
3 replies

Apr 4, 2016 5:52 AM in response to lqfocus06

No, you do not need to re-format your hard drive. You will need to download GPT Fdisk - https://sourceforge.net/projects/gptfdisk/ - and after you install it, run it and access the E(x)pert menu, and then use the 'n' command to remove the MBR. Do not forget to 'p'rint and 'w'rite it.


Please be aware that 2011 Macs are preUEFI and your sound and GPU may not work properly.


sudo gdisk /dev/disk0

Password:

GPT fdisk (gdisk) version 1.0.0


Warning: Devices opened with shared lock will not have their

partition table automatically reloaded!


Partition table scan:

MBR: hybrid

BSD: not present

APM: not present

GPT: present


Found valid GPT with hybrid MBR; using GPT.


Command (? for help): x


Expert command (? for help): ?

a set attributes

c change partition GUID

d display the sector alignment value

e relocate backup data structures to the end of the disk

g change disk GUID

h recompute CHS values in protective/hybrid MBR

i show detailed information on a partition

l set the sector alignment value

m return to main menu

n create a new protective MBR

o print protective MBR data

p print the partition table

q quit without saving changes

r recovery and transformation options (experts only)

s resize partition table

t transpose two partition table entries

u replicate partition table on new device

v verify disk

w write table to disk and exit

z zap (destroy) GPT data structures and exit

? print this menu

Apr 4, 2016 7:07 AM in response to Loner T

I got the following error


Do you want to proceed? (Y/N): Y

OK; writing new GUID partition table (GPT) to /dev/disk0.

Warning: Devices opened with shared lock will not have their

partition table automatically reloaded!

Unable to open device '/dev/disk0' for writing! Errno is 1! Aborting write!


Do I need to disable something while in recovery, in terminal? This was something I found while researching for ways.

MBR partition table, only GPT disk

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