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Convert Windows 10 Partition to GPT?

I have succeeded in installing the latest version of Windows 10 onto the 1 TB hard drive of my Mac mini 2012 with Boot Camp, reserving my 1 TB SSD for macOS High Sierra (10.3.3). However, I was unable to install Windows while the hard disk had a GUID partition map, instead having to convert it to MBR before installing Windows 10. I understand there are several advantages to using the GUID partition map, and so I was wondering if there is any way to convert my Windows 10 disk to GUID.


This is the output of diskutil list in Terminal:

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.1 TB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_APFS Container disk2 1.1 TB disk0s2


/dev/disk1 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: FDisk_partition_scheme *1.0 TB disk1

1: Windows_NTFS System Reserved 575.7 MB disk1s1

2: Windows_NTFS BOOTCAMP 999.6 GB disk1s2


/dev/disk2 (synthesized):

#: TYPE NAME SIZE IDENTIFIER

0: APFS Container Scheme - +1.1 TB disk2

Physical Store disk0s2

1: APFS Volume Macintosh HD 847.5 GB disk2s1

2: APFS Volume Preboot 24.7 MB disk2s2

3: APFS Volume Recovery 507.2 MB disk2s3

4: APFS Volume VM 3.2 GB disk2s4

Mac mini, macOS High Sierra (10.13.3), Late 2012

Posted on Mar 11, 2018 3:50 PM

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Question marked as Best reply

Posted on Mar 11, 2018 4:30 PM

mbenson2 wrote:


Thank you for the quick response. I have configured the drive as a fusion drive in the past, but I tried again after installing High Sierra, and Boot Camp ran into trouble partitioning the drive. Besides, I like being able to use APFS.

HS has quite a few Bootcamp-related issues. I do not recommend HS, if you also need Windows. Sierra is much more stable. APFS also creates other disk space challenges.


mbenson2 wrote:



If I reinstall Windows, will I be able to use GPT if I do something differently during the installation?


Not during the installation, but you can before the installation. If you really want APFS, and Windows, manual partitioning is the better approach. For example, half the SSD as APFS, the second half+HDD as Fusion, and a manual partition using diskutil cs resizeStack for Windows from the Fusion drive.


mbenson2 wrote:


Also, the main reason I asked this question is because my computer is slow to switch between operating systems, and I was wondering if there is any way to speed up this process. Thanks.

EFI booting is in general faster, but a preUEFI Mac does not fully support it. Late 2013 and later models are UEFI-compliant. You can install Windows on the SSD part, if you manually partition. There are more esoteric schemes, but macOS upgrades/updates do not handle non-standard partitioning well.

13 replies
Question marked as Best reply

Mar 11, 2018 4:30 PM in response to mbenson2

mbenson2 wrote:


Thank you for the quick response. I have configured the drive as a fusion drive in the past, but I tried again after installing High Sierra, and Boot Camp ran into trouble partitioning the drive. Besides, I like being able to use APFS.

HS has quite a few Bootcamp-related issues. I do not recommend HS, if you also need Windows. Sierra is much more stable. APFS also creates other disk space challenges.


mbenson2 wrote:



If I reinstall Windows, will I be able to use GPT if I do something differently during the installation?


Not during the installation, but you can before the installation. If you really want APFS, and Windows, manual partitioning is the better approach. For example, half the SSD as APFS, the second half+HDD as Fusion, and a manual partition using diskutil cs resizeStack for Windows from the Fusion drive.


mbenson2 wrote:


Also, the main reason I asked this question is because my computer is slow to switch between operating systems, and I was wondering if there is any way to speed up this process. Thanks.

EFI booting is in general faster, but a preUEFI Mac does not fully support it. Late 2013 and later models are UEFI-compliant. You can install Windows on the SSD part, if you manually partition. There are more esoteric schemes, but macOS upgrades/updates do not handle non-standard partitioning well.

Mar 15, 2018 6:53 PM in response to mbenson2

Once Windows is installed, you will run into issue switching partition formats. If you have more than one disk in the Mini, you can install on a GPT partition, if the two drives are configured as a Fusion drive.


Be aware that your Mini is a preUEFI Mac, so an EFI installation will not work properly, so it must be a legacy BIOS installation.

Mar 11, 2018 4:07 PM in response to Loner T

Thank you for the quick response. I have configured the drive as a fusion drive in the past, but I tried again after installing High Sierra, and Boot Camp ran into trouble partitioning the drive. Besides, I like being able to use APFS.


If I reinstall Windows, will I be able to use GPT if I do something differently during the installation?


Also, the main reason I asked this question is because my computer is slow to switch between operating systems, and I was wondering if there is any way to speed up this process. Thanks.

Mar 12, 2018 12:34 PM in response to Loner T

Okay--I was able to do that, and it decreased OS switching time dramatically.


Also, the SSD I use is a Crucial drive, and I’ve been playing around with the Crucial Storage Executive software. I was wondering if using the over-provisioning option would noticably increase boot speeds. If so, would it be likely to cause any problems with the disk structure?


Just to make sure you understand my current setup, here is the output of diskutil list:

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.1 TB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_APFS Container disk2 1.0 TB disk0s2

3: Microsoft Basic Data BOOTCAMP 48.0 GB disk0s3


/dev/disk1 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk1

1: EFI EFI 209.7 MB disk1s1

2: Microsoft Basic Data STORAGE 1000.0 GB disk1s2


/dev/disk2 (synthesized):

#: TYPE NAME SIZE IDENTIFIER

0: APFS Container Scheme - +1.0 TB disk2

Physical Store disk0s2

1: APFS Volume Macintosh HD 847.7 GB disk2s1

2: APFS Volume Preboot 24.7 MB disk2s2

3: APFS Volume Recovery 507.2 MB disk2s3

4: APFS Volume VM 2.1 GB disk2s4

Mar 18, 2018 4:52 PM in response to Loner T

I was able to get everything working the way I want it to. I downgraded to macOS Sierra and set up Boot Camp that way, giving the Boot Camp partition enough space for Storage Executive to over-partition the recommended amount of storage space. I don't notice too much of a speed increase, but that's okay.


The only issue I'm having is that when I'm in Windows, click the Boot Camp icon, and then click start in OS X, the startup disk preference pane has neither partition selected once the computer boots up. I always have to manually select Macintosh HD. Is there any way around this?

Mar 18, 2018 5:43 PM in response to Loner T

I'm on Sierra, with an HFS+ volume. Here is the diskutil list:

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.1 TB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 820.4 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data BOOTCAMP 229.0 GB disk0s4


/dev/disk1 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk1

1: EFI EFI 209.7 MB disk1s1

2: Apple_HFS MacStorage 749.5 GB disk1s2

3: Microsoft Basic Data WinStorage 250.2 GB disk1s3

Convert Windows 10 Partition to GPT?

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