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DeadeyeM

macrumors regular
Original poster
Jun 12, 2012
193
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Fresh install of Mojave, so installing Bootcamp Win10 was no issue. BCA loaded fine and flashed USB key with Win then installed Win 10 no issues.

So what i've noticed:
- In Windows BCA there is no option to target Mac disk, so to boot into Mac partition upon restart you have to hold Option key (or was it Command?)

- In Mojave when loading BCA i don't get an option to merge the Bootcamp partition back as a single drive in Mac, it might be due to APFS my machine being formatted to, screen shot attached.

So anyone installing Bootcamp be-aware that partitioning under APFS is one time think, if you want to merge BC to Mac you have to format all drivers.
 

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Hi, Thanks for these findings. I had a similar experience trying to install Win10.

I have a 2012 MBP 9,1 (unibody, non-retina) with one APFS formatted SSD running 10.14.6 and and a superdrive installed.

Method #1 - Similar "SUCESS"
I was able to use the BCA to install Win 10 via the BCA USB method. I used a 16GB USB2 stick. Partitioning with in BCA, Installation, BCA even made a NTFS partition that Windows liked, rebooting and BC driver installation was painless, for once. Once in Win10, rebooting into MacOS from Win10 I wind up with the Mac restore partition mounting. A warm boot from Win10 or a cold boot after running Win10, results in the EFI not being able to see Mac 10.14.6 partition and instead mounts the restore partition. So, I must at the right moment after the chime hold down the option key to get into the boot picker and Pick Mojave. Once in Mojave I can warm reboot & cold boot back into Mojave no problem. I can also use the Start Up Disk pref pane to boot into BootCamp, no problem. Of course I would prefer not to have this hick-up requiring the use of the boot-picker...

I thought this was an issue due to the USB install method being in UEFI mode and such as the cMP 5,1 owners are dealing with and that I had to install from a DVD to be able to install via "Legacy Bios and MBR format".

I created a DVD using the Windows Create Media Tool, running Win10 from my MBP and it burned an install DVD.

Method #2 - FAIL
I used BCA to remove my Win10 portion (no issues) and started over again, only to find theat BCA v6.1 would not allow me to use a DVD. Halfway through the BCA install I was able to switch over to my DVD installer of Win10, seemed to install fine until the first reboot and now it thinks the Win10 install is damaged or needs to be re-installed.

For all the headache and time wasted I am thinking to revert to Method #1. Searching the web I have not found that Method #2 is even needed for a MBP, but, this thread was the first to point put the boot picker issue using the official BCA method #1.

LMK if anyone has any tips... Thanks!
 
Last edited:
Apparently Win10 can't see MacOS on an APFS disk.

This might be the way forward for me:

Install via BCA w/USB Method #1,
Keep the Mac Start Up Disk Pref Pane set to boot 10.14 and use the EFI boot picker only to boot into Win10, since I o don't need Win10 very often! YMMV.

From: https://forums.macrumors.com/threads/bootcamp-mojave-mess.2189893/?post=27542860#post-27542860

"So, how to prevent booting into Windows, then?
ALWAYS use the Option-boot picker screen when you reboot. That assures that you are choosing the correct startup system. You would ALWAYS have to use the Option key when the system restarts, unless you KNOW that is set for the drive you want to use.
Best way forward, is to boot to macOS, open the Startup Disk pref pane. Select your macOS boot system.
Restart should NOW be in macOS. If you need to restart to your Windows system, hold the Option key and select that system.
Because you changed the Startup Disk to macOS, then a simple restart should then boot to your macOS system."
 
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