Unable to install Windows 10

Download and install GPT FDisk from https://sourceforge.net/projects/gptfdisk/ .

Rebuild MBR to match the new GPT information thus resetting the Hybrid MBR. Use defaults for other questions (like partition codes). The only values that need modifications are the Boot flags and step 10. Accept all other defaults that Gdisk offers. Please see thesample Q&A as an example. These steps can be repeated if you make a mistake before you get to Step 12, otherwise start from Step 1 for these steps. Step 6 has numbers which are typed with a space between the numbers. Please see the sample Q&A before you execute these steps.

1. Sudo gdisk /dev/rdisk0
2. P (Print list of parts)
3. R (Recover)
4. O (print current Hybrid MBR)
5. H (chooses Hybrid)
6. Partitions numbers to be hybridized: 2 3
7. Y (Good for GRUB question)
8. N (part 2 boot flag)
9. Y (part 3 boot flag make NTFS bootable partition)
10. O (print current Hybrid MBR)
11. W (Write the new MBR)
12. Y (Yes! write the new MBR)
13. Reboot

Here is sample Q&A for this section. Please notice the Press Enter/Return.

Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N): Y

Creating entry for GPT partition #2 (MBR partition #2)

Enter an MBR hex code (default AF): Press Enter/Return

Set the bootable flag? (Y/N): N

Creating entry for GPT partition #3 (MBR partition #3)

Enter an MBR hex code (default 07): Press Enter/Return

Set the bootable flag? (Y/N): Y

Test 1 - Does Bootcamp Volume show up in Finder?

Test 2 - Can you see files in Bootcamp Volume?

Test 3 - Can you select Bootcamp in System Preferences -> Startup Disk?

Test 4 - If Test 3 is successful, select Bootcamp and Click Restart.

The steps should be

• Boot into Internet Recovery and rebuild the APFS Fusion to CoreStorage Fusion. You should backup any important files before you do this.
• Install Sierra
• Run BC Assistant and partition and install Windows. Ensure that you use EFI Boot.
• Once you have verified both OSes, upgrade Sierra to Mojave
• Verify both OSes again

Ananbe wrote:

I guess the only way for Windows to work is to convert GPT to MBR. Is this what I should do? http://www.rodsbooks.com/gdisk/mbr2gpt.html

Please do not. We need to create a Hybrid MBR.

Can you post the output of

sudo gpt -vv -r show /dev/disk0

Your 1TB disk should not be a MBR disk. Can you post the output of

gpt -vv -r show /dev/disk1

Ananbe wrote:

I'm just curious. Is this really a good idea? It seems like it'll be a downgrade to go from GPT to MBR. I don't know why I couldn't install windows before with EFI and GPT. Do you have an idea why?

Your installation came from Yosemite, which should have been BIOS/MBR. Mojave upgrade removed the MBR, that Yosemite had in place. If you can see Windows files, the NTFS part is intact, but boot-ability is missing, due to the missing MBR.

If you want to install using EFI, the current installation cannot be converted. It must be removed and you should choose EFI, but you will back to your original issue.

2013-2014 Macs which support both EFI and BIOS seem to have issues with Mojave and the corresponding BCA.

Do you have a Fusion drive?

Can you post the output of

diskutil list

Can you try W10 1709?

Can you post the output of

sudo fdisk /dev/disk0

You may need to temporarily disable SIP using csrutil in Local Recovery.

Can you post a screen shot of what you see?

If you have wiped the storage, I suggest installing macOS Sierra, and installing Windows. Once Windows is fully installed and verified, then you can upgrade Sierra to macOS Mojave.

Are you able to boot into macOS and rebuild the MBR?

      409640  1370079192      2  GPT part - 7C3457EF-0000-11AA-AA11-00306543ECAC

This should not result into AF in the MBR.

Also, if you are prompted to add entries for additional space, say ‘n’ and continue.

Is Windows still installed on the Mac? If yes, are you able to boot into Windows Safe Mode?

Was the WININSTALL USB created by BCA? Is it a USB2 Flash drive?