Contribute
Register

Dual Boot Partitions Messed Up

Joined
May 25, 2020
Messages
9
Motherboard
Gigabyte GA-H77-D3H
CPU
3.4GHz Quad-Core Intel i5
Graphics
NVidia GeForce GTX 650 1023 MB
Mac
  1. MacBook Pro
Mobile Phone
  1. iOS
I am trying to dual boot OSX and Windows 10 on my desktop hackintosh. OSX is fully installed, and I have created Windows 10 install media on a flash drive. I am able to boot into the installer, but when I tell the installer to install in the unallocated space (~250gb), it creates 4 partitions in such a way that the Recovery partition ends up being mounted as the C: drive which prevents anything from being installed. (Giving me the error: could not prepare the computer for boot as soon as the installer starts trying to copy files) I have tried to reassign the partitions so that the main partition is assigned to the C: drive, but when I try to install after doing this, the installer cannot recognize my partitions because of the existing OSX partitions. The installer gives me the error "We couldn't create a new partition or locate an existing one." How can I fix this so the install will start working?

I should also note that I only have one drive, and am trying to install both operation systems onto that drive, so I am not able to simply disconnect the OSX partitions.

My drive is formatted as GUID partition table and I have ensured that my bios settings boot in UEFI mode.

Please let me know if there is a better forum category to put this in, I looked around, but did not see anything specific to my situation.
 
Last edited:

P1LGRIM

Moderator
Joined
Mar 2, 2012
Messages
24,718
Motherboard
Lenovo ThinkStation p300 ⌘
CPU
i7-4790K
Graphics
HD 4600
Mac
  1. MacBook Pro
  2. Mac mini
Classic Mac
  1. Power Mac
Mobile Phone
  1. iOS
Moved to Multi Booting.
 

Going Bald

Moderator
Joined
Aug 14, 2010
Messages
23,238
Motherboard
GA-X58A-UD7-F7
CPU
W3670
Graphics
RX 580
Mac
  1. iMac
  2. MacBook Pro
  3. Mac mini
Classic Mac
  1. iMac
Mobile Phone
  1. Android
Please let me know if there is a better forum category to put this in, I looked around, but did not see anything specific to my situation.
See pinned guide at the beginning of this forum.
 
Joined
May 25, 2020
Messages
9
Motherboard
Gigabyte GA-H77-D3H
CPU
3.4GHz Quad-Core Intel i5
Graphics
NVidia GeForce GTX 650 1023 MB
Mac
  1. MacBook Pro
Mobile Phone
  1. iOS
See pinned guide at the beginning of this forum.

That was the guide I was following. I did everything the same as that guide, but after I create the free space at the end of my drive and hit next, the windows installer gives me the error "Could not prepare the computer for boot"

I have attached screenshots of my drive structure before starting the installer and the error.
 

Attachments

  • IMG_0559.JPG
    IMG_0559.JPG
    2.7 MB · Views: 27
  • IMG_3757.JPG
    IMG_3757.JPG
    2.7 MB · Views: 25

Going Bald

Moderator
Joined
Aug 14, 2010
Messages
23,238
Motherboard
GA-X58A-UD7-F7
CPU
W3670
Graphics
RX 580
Mac
  1. iMac
  2. MacBook Pro
  3. Mac mini
Classic Mac
  1. iMac
Mobile Phone
  1. Android
This error generally happens when the installer is for MBR Legacy installs and cannot install on GPT+ formatted drives. Make sure your installer is for installing on UEFI and not Legacy BIOS.
 
Joined
Jul 4, 2012
Messages
372
Motherboard
Gigabyte Aorus Z390 Ultra
CPU
i5-9600K
Graphics
Vega 56
Mac
  1. iMac
  2. MacBook Pro
Mobile Phone
  1. iOS
That was the guide I was following. I did everything the same as that guide, but after I create the free space at the end of my drive and hit next, the windows installer gives me the error "Could not prepare the computer for boot"

I have attached screenshots of my drive structure before starting the installer and the error.

I've installed Windows in a couple of different ways and putting windows on it's own drive and disconnecting macOS is the best and most reliable way. Your chipset doesn't have NVMe so you are using SATA and it's just not that hard to unplug a SATA cable. Also SATA drive, even SSDs are cheap right now.

When you boot the Windows installer you can us F12 and choose the option that starts with UEFI. Older boards often default to MBR booting first, and that defines which gets installed.

I personally always disable legacy and CSM in the bios so I don't need have to deal with the issue.
 
Joined
May 25, 2020
Messages
9
Motherboard
Gigabyte GA-H77-D3H
CPU
3.4GHz Quad-Core Intel i5
Graphics
NVidia GeForce GTX 650 1023 MB
Mac
  1. MacBook Pro
Mobile Phone
  1. iOS
This error generally happens when the installer is for MBR Legacy installs and cannot install on GPT+ formatted drives. Make sure your installer is for installing on UEFI and not Legacy BIOS.
I have been selecting the uefi option at boot, and I just verified that the windows installer is booted in UEFI (image attached). Is there any difference between booting the installer in UEFI and the installer actually being for UEFI?
 

Attachments

  • IMG_4223.JPG
    IMG_4223.JPG
    2.2 MB · Views: 23
Joined
May 25, 2020
Messages
9
Motherboard
Gigabyte GA-H77-D3H
CPU
3.4GHz Quad-Core Intel i5
Graphics
NVidia GeForce GTX 650 1023 MB
Mac
  1. MacBook Pro
Mobile Phone
  1. iOS
I've installed Windows in a couple of different ways and putting windows on it's own drive and disconnecting macOS is the best and most reliable way. Your chipset doesn't have NVMe so you are using SATA and it's just not that hard to unplug a SATA cable. Also SATA drive, even SSDs are cheap right now.

When you boot the Windows installer you can us F12 and choose the option that starts with UEFI. Older boards often default to MBR booting first, and that defines which gets installed.

I personally always disable legacy and CSM in the bios so I don't need have to deal with the issue.

I only have one drive unfortunately, and I would prefer not to purchase another one, especially since all the guides I have found make this seem like it should be doable.

I have also verified when in the windows installer, that it has been booted in UEFI mode.
 

Going Bald

Moderator
Joined
Aug 14, 2010
Messages
23,238
Motherboard
GA-X58A-UD7-F7
CPU
W3670
Graphics
RX 580
Mac
  1. iMac
  2. MacBook Pro
  3. Mac mini
Classic Mac
  1. iMac
Mobile Phone
  1. Android
I have been selecting the uefi option at boot, and I just verified that the windows installer is booted in UEFI (image attached). Is there any difference between booting the installer in UEFI and the installer actually being for UEFI?
If the installer boots when you select the UEFI USB and gets to the install screen, then it is booting UEFI and will install UEFI. Try clicking on the free space to select it, click on New to create a new volume, format it NTFS and then click on Next to continue the installation.
 
Joined
May 25, 2020
Messages
9
Motherboard
Gigabyte GA-H77-D3H
CPU
3.4GHz Quad-Core Intel i5
Graphics
NVidia GeForce GTX 650 1023 MB
Mac
  1. MacBook Pro
Mobile Phone
  1. iOS
If the installer boots when you select the UEFI USB and gets to the install screen, then it is booting UEFI and will install UEFI. Try clicking on the free space to select it, click on New to create a new volume, format it NTFS and then click on Next to continue the installation.

When I click on new, it automatically creates 4 volumes, just the same as it does when I try to proceed with the installer on the unallocated space.
 
Top