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1TB 5k iMac issue with Bootcamp

Hey All,

I know you have probably come across this a few times but I have been dealing with Apple support and they have offered me no help.

I had a MBP before and has no issues installing windows but i have tried windows 7/8/and 10 tech preview and it hasnt worked.

it is telling me that i need to partition it to NTFS or it wont install when i am in windows install. i have tried doing this and deleting the partition, i have tried formatting in windows, i have even tried getting a third party ntfs file format for osx. all have failed.

please help. i bought a $3000 machine with no support for windows it seems 😟

thanks!

-Marco

iMac with Retina 5K display, Mac OS X (10.0.x)

Posted on Apr 21, 2015 9:01 AM

47 replies

Loner T

Level 9

59,471 points

Apr 21, 2015 7:54 PM in response to Marcanthonynoz

If the following steps work, then I need to file a bug report with Apple.

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 6. Accept all other defaults that Gdisk offers.

Sudo gdisk /dev/disk0
P (Print list of parts)
R (Recover)
H (chooses Hybrid)
Partitions numbers to be hybridized: 2 3 4
Y (Good for GRUB question)
N (part 2 boot flag)
N (part 3 boot flag)
Y (part 4 boot flag make NTFS bootable partition)
O (print the updated MBR)
W (Write the new MBR)
Y (Yes! write the new MBR)
Reboot

Here is a sample Q&A. Please notice the Press Enter/Return to accept defaults.

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 AB): Press Enter/Return

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

Creating entry for GPT partition #4 (MBR partition #4)

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

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

Apr 21, 2015 7:58 PM in response to Loner T

ok im sorry man, im confused! lol

so what exactly should i be typing into terminal? (Sorry not too saavy with this stuff)

Apr 21, 2015 7:58 PM in response to Loner T

also, will this erase my drive?

Loner T

Level 9

59,471 points

Apr 21, 2015 8:06 PM in response to Marcanthonynoz

My reply got cut-off. 😟. I also have a typo. It should be disk1 not disk0. This will not touch any data on your drive or erase it. It creates a 1:1 mapping between your GPT and the MBR that Windows is supposed to see.

Please download http://sourceforge.net/projects/gptfdisk/ and install it. Once it is installed, go to Terminal, and type

sudo gdisk /dev/disk1

The rest of the commands are typed in when prompted by Gdisk. The notes in "()" indicate the function the one-character command performs.

Apr 21, 2015 8:13 PM in response to Loner T

alright

done and done

what now? 🙂

Loner T

Level 9

59,471 points

Apr 21, 2015 8:43 PM in response to Marcanthonynoz

Run BCA and try to install Windows. You do not need to create a new partition. One option is to use your USB, power cycle your Mac, and hold he Option key and choose the USB Windows. Please do not choose EFI boot, otherwise you will get partition mismatch about GPT and MBR.

Apr 21, 2015 8:50 PM in response to Loner T

alright so when i shut my mac off and reboot using option i go into windows and all that happens is a cursor at the top left keeps blinking.

nothing else :s

should i repartition again?

Loner T

Level 9

59,471 points

Apr 21, 2015 9:15 PM in response to Marcanthonynoz

If you repartition, you may end up in the same place, and the steps we executed, will get cleaned out. In the set of steps you executed, because Windows is not installed yet, the blinking cursor is because of step 9. Can you execute the same steps and change step 9 to 'N' and test?