Q: Windows 10 Boot Camp Partition Won't Boot After Moving to New Mac via Winclone

I did run Sysprep, but since the original Windows installation was Windows 7 upgraded to Windows 10, it would not allow it.

I did also confirm that the image was EFI bootable. I even converted to legacy MBR and back to EFI bootable volume in Winclone, on the recommendation of Winclone support, but I still can't get it to boot.

When you say "Your Mid-2011 MBA should be a legacy BIOS/MBR Windows installation, and it will only work as one on the new Mac," do you mean that I would need to convert the Windows installation from an MBR partition to a GPT bootable partition?

I downloaded GPT fdisk, and it reports the following partition table list, as well as additional information on the Windows Boot Camp partition:

So, I'm just confused as to why I can see the volume and read files from it without any problems, but when I attempt to boot to it, the system immediately takes me right into OS X, it's like it doesn't even try to boot to Windows--no error messages or anything.

Thanks in advance!

Output from Gdisk 'o' 'r' commands:

Disk size is 977105060 sectors (465.9 GiB)

MBR disk identifier: 0x028A47A7

MBR partitions:

Number  Boot  Start Sector  End Sector  Status      Code

  1                    1    977105059  primary    0xEE

Output from sudo fdisk /dev/disk0:

Disk: /dev/disk0    geometry: 60821/255/63 [977105060 sectors]

Signature: 0xAA55

         Starting       Ending

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

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

1: EE 1023 254  63 - 1023 254  63 [         1 -  977105059] <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

Thanks!

I've got to be honest, I'm a little nervous to do this, for fear that I might foul up my OS X installation partition. From what I've read, Hybrid MBRs are "flaky and unreliable."

I was able to figure out how to get my old Windows 10 partition to boot on my new Mac without needing to mess with Gdisk (which I just didn't feel comfortable with). Here are the steps:

• Make a backup image of the old Windows Boot Camp partition on the old Mac using Winclone
• Delete any existing Windows partitions from the new Mac using the Boot Camp Assistant or Disk Utility in OS X
• Download the Windows 10 ISO
• Use Boot Camp Assistant to create a Windows install disk with a USB drive, and create a new partition, using the slider to adjust how much space you want the Windows partition to consume
• With the Windows install USB drive plugged in, restart and hold down Option, then select EFI Boot to begin the Windows installation process (boot to the USB drive with the Windows install disk)
• Go through the Windows 10 install process, clicking "Skip" when asked for the product key (we will be overwriting this partition in a later step--this is just to get the boot partition table--or GPT--setup properly)
• After the machine boots successfully to Windows, and you are able to boot into Windows by holding down Option when rebooting, boot back into OS X
• Assuming you've already imaged your Windows 10 partition with Winclone on the old Mac and transferred it to the new Mac (or loaded it from a shared network drive), launch Winclone, load the previously saved Windows image, and restore it to the newly created Windows 10 partition (it will wipe away the temporary install just created)
• Use Boot Camp Assistant to create a USB disk with the correct Boot Camp drivers for Windows
• Reboot and hold down Option, then select the restored Windows partition, and it should boot into Windows (alternatively, you can boot to Windows using System Preferences -> Startup Disk)
• Install the updated Windows device drivers using the Boot Camp drivers USB disk just created, then restart

Perhaps the partition table did not get setup properly when migrating from the old Mac to the new one in my first attempts using Winclone. I believe that going through a plain vanilla install of Windows 10 using the ISO and Boot Camp Assistant properly sets up the partition table and enables you to then restore and boot into the restored Windows image. Hooray, for not having to re-install and setup Windows and configure apps and settings again!

Here is the output of the same commands issued previously after I went through the installation procedure above manually installing Windows 10 via an ISO, then re-imaging with Winclone:

sudo fdisk /dev/disk0:

Disk: /dev/disk0    geometry: 60821/255/63 [977105060 sectors]

Signature: 0xAA55

        Starting      Ending

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

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

1: EE 1023 254  63 - 1023 254  63 [        1 -  977105059] <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

sudo gdisk /dev/disk0:

  MBR: protective

  BSD: not present

  APM: not present

  GPT: present

then 'p':

Disk /dev/disk0: 977105060 sectors, 465.9 GiB

Logical sector size: 512 bytes

Disk identifier (GUID): 5F61EF0E-F78A-4B21-991F-0CCDFDE228CB

Partition table holds up to 128 entries

First usable sector is 34, last usable sector is 977105026

Partitions will be aligned on 8-sector boundaries

Total free space is 1225 sectors (612.5 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name

   1              40          409639   200.0 MiB   EF00  EFI System Partition

   2          409640       803853471   383.1 GiB   AF05  Customer

   3       803853472       805123007   619.9 MiB   AB00  Recovery HD

   4       805124096       977104895   82.0 GiB    0700  BOOTCAMP

then 'r', 'o':

Disk size is 977105060 sectors (465.9 GiB)

MBR disk identifier: 0x028A47A7

MBR partitions:

Number  Boot  Start Sector   End Sector   Status      Code

   1                     1    977105059   primary     0xEE

Perhaps the manual process I followed didn't necessarily change much in the way of partitions, as it looks to be about the same as before, but maybe it was the contents of the EFI volume, or something else that finally convinced the Mac to allow booting from the Windows partition.