cant boot into OSX after installing Windows 10 via bootcamp

Question

cant boot into OSX after installing Windows 10 via bootcamp

Hello, I need help.

I tried to install Windows 10 via bootcamp, and I did successfully with no problems. However, after installing, I restarted my computer, hold option key and tried to boot into OS X, but it wont work. it would bring a symbol than boot me to windows 10 !

any solutions? I don't have a backup for my files in OSX, will I lose my files?

NOTE: when I formatted the partition for windows, it didn't say bootcamp next to it but it was clearly the partition I was supposed to format, it was the same size I decided to make for Windows when I was in bootcamp in OSX + it was 100% empty.

MacBook Pro (Retina, 15-inch, Late 2013)

Posted on May 26, 2016 12:04 AM

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Answer 1

May 26, 2016 1:28 AM in response to Suliman Alsarraf

UPDATE 1: So i managed to get into internet recovery, and erased the partition that had the Windows and installed Marverix OSX instead (temporarily ) also i repaired the MACINTOSH HD hard drive, but now i can't boot it up at all when i press the option button when booting up the mac. any solutions?

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Answer 2

Loner T

Level 9

59,526 points

May 27, 2016 3:41 AM in response to Suliman Alsarraf

Your 2013 Bootcamp layout should look like

And the original BC Assistant-created partition is a FAT32 partition, which needs to be reformatted to NTFS as shown.

If you use any other method of manipulation of the disk partitions and are not careful, you can cause problems.

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Answer 3

Loner T

Level 9

59,526 points

May 27, 2016 2:42 AM in response to Suliman Alsarraf

If you choose the incorrect partition for Windows installation, or manipulate the partitions using Windows Disk Management, you disk can be converted to an MBR disk, which prevents OS X from booting. OS X needs a GPT/EFI disk to boot. Since you have rebuilt your Mac, there is no way for me to prove it to you.

Unable to boot into mac or bootcamp has a similar issue where disk0 became a Windows LDM disk.

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Answer 4

Loner T

Level 9

59,526 points

Jun 18, 2016 12:14 PM in response to Mattwolfson

If you format the incorrect partition, OS X will not boot. If BC drivers are not install correctly, the Control Panel Bootcamp item will not work, or will not be available again.

Please also see Boot Camp: Set the default operating system .

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Answer 5

Loner T

Level 9

59,526 points

May 26, 2016 6:10 PM in response to Suliman Alsarraf

Boot into Internet Recovery, run Utilities -> Terminal, run the command diskutil list and copy the output using Command+C, exit Terminal, start Safari and paste the output of the command that you just copied.

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Answer 6

May 26, 2016 11:08 PM in response to Loner T

Thanks for the reply, what does posting the command do? do you mean i should google it? and i formatted the partition that has Windows 10 and installed Mavericks OS on it, and i can see all my filed in the other partition that had my main OS X ( El capitan ) and copied the files i needed ( college, etc .. ) and than formatted both of the partitions, merged them and installed Mavericks again and updated it to El capitan and everything returned to normal, lost my apps etc but its okay.

I just want to know why did this happen because I'm willing to try and install windows again at some point

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Answer 7

May 27, 2016 2:57 AM in response to Loner T

Okay, the only thing that i wasn't sure of is when i went to setup Windows, i thought that the partition i made for it is spoused to be called "Bootcamp" but it wasn't, but i formatted it and installed Windows in it anyways because it was the same exact size that i allocated for Windows in Bootcamp Assistant. However, like i said the partition wasn't under the name "Bootcamp" is that possibly the reason? because i didn't play with windows at all it only installed the drivers and than rebooted my mac, made sure everything looked good and than wanted to switch back to OS X but than it didn't work for some reason \:

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Answer 8

Loner T

Level 9

59,526 points

May 28, 2016 3:53 PM in response to Suliman Alsarraf

If you format the incorrect partition, it changes the entire disk, which causes problems with OS X. Can you boot into Internet Recovery, start Utilities -> Terminal, run

diskutil list

Copy the output and quite Terminal, start Safari, and paste it as a reply on this discussion.

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Answer 9

Jun 18, 2016 9:51 AM in response to Loner T

I have the OP's exact same issue, or had - I had to completely wipe my system because of it. I am new to Mac (just picked up a MBP today) but pretty technically adept. I followed the Bootcamp instructions to the T for Windows 10 on El Cap and Windows installed fine, but I couldn't access my OS X partition after rebooting. I recall having to reformat the Windows drive (the BOOTCAMP partition) through the Windows/Bootcamp installer and originally thought that was the issue, but I double-checked the Apple walkthrough and it was correct.

Is it always user error that causes this error? I won't rule out user error, but I am really cautious to do this again. I bought this unit knowing I could use Windows, via Bootcamp so this is a priority. However, I had to end up wiping the entire SSD to get the partitions to merge again. This took me hours... so I am looking for a little confidence in doing the Boot Camp process all over again.

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Answer 10

Jun 18, 2016 11:30 PM in response to Loner T

This makes sense and on second thought it may be an issue with the BC drivers. I thought everything was installed correctly, but I noticed there was no Boot Camp application within the Windows instance. I also noticed nothing in the task bar. Is there an obvious message that the installation was successful? I am going to backup my unit on Time Machine and try this again later today, hopefully with better results.

Best,

Matt

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Answer 11

Jun 20, 2016 6:07 AM in response to Loner T

Too late! However, I did use the recovery and it worked to restore OSX to a working state. That being said, there was still a blank Windows partition that was taking up space, but I was unable to modify it in Disk Utility (or Disk Utility in Recovery). I ended up wiping, buying an external hard drive and Time Machining. I reinstalled Boot Camp and it works flawlessly now. Appreciate the support.

Matt