OSX Yosemite breaks Bootcamp

It has worked for some, not for others. If you are gong to try, make a full backup of the Mac partition (Time Machine) and one of the Windows partition (Winclone) before you even think about starting.

I Installed Yosemite beta and it wiped out my bootcamp. I had done a complete backup and restoring did not fix the problem. I am anxious to install the official release of Yosemite but have been searching for the answer to this same question. I'm going to wait until more feedback is available before downloading.

Please see "Missing Operating system_ " After installing Yosemite . It also breaks the read-only capability between OS X and Windows partitions.

when I got the dialog I saw that it had the option of partition it should install yosemite on and I of cause choose mac hd rather then my windows partition

kinda scary to think that what goes on on one partition could affect the other

I just successfully installed Windows 8.1 Update 1 on BootCamp on Mac OS X Yosemite. Here is a step by step I just wrote, hope it helps y'all:

How to successfully install Windows 8, or above, on Mac OS X Mavericks or above:

Requirements:

1- Windows OS ISO Image file

2- An 8GBs USB Flash Drive

3- A good Internet connection as you will need to download the Windows compatible drivers for your Mac

Steps:

1- Open up Disk Utility and create an additional partition for Windows formatted as ExFat. 100GBs, or above, is recommended as update to the operating system, as well as Apps requiere space on your HD or SSD [This step can be done during Mac OS X's installation process]

2- Open up BootCamp Assistant

3- Make sure only the 'Create a Windows 7 or later version install disk' is checked and your USB Flash Drive plugged in and click 'Continue'

4- Click 'Choose' and select your Windows ISO Image file

5- Select the USB Flash Drive you will be using during the installation process and click continue to confirm

6- Once done, restart your Mac and hold down the 'alt/option' key on your keyboard to bring up the Boot Menu

7- Select the USB Flash Drive named Windows, not the UEFI Boot

8- Install Windows as you normally would

* Remember to press and hold the 'alt/option' key, and select the Windows Partition, whenever the installation process requires your Mac to restart

* http://msdn.microsoft.com/en-us/library/windows/apps/jj945423.aspx

* http://windows.microsoft.com/en-us/windows-8/install-windows-on-mac

Thanks. I would add, consider installing the Trackpad++ driver after step 8 to get the normal trackpad features in Boot Camp 😊 .

What version of the beta are you on? it broke mine when i upgraded... I'm on beta 6 atm and I'm going to try again i haven't tried sense beta 2 so maybe they fixed it.

Yosemite broke quite a few Bootcamp installations because it manipulated Bootcamp GPT and MBR incorrectly and broke it. I saw the same thing in Mavericks. During DP 1-6, I had provided feedback saying this would break customers existing installation. It seems to have been ignored to meet the Yosemite launch date.

Hi Loner,

Unfortunately, should have read this before upgrading the yosemite while having the bootcamp.

I have noticed you have successfully advised some users on recovering the windows files and data.

I have followed your notes:

diskutil list

/dev/disk0

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *251.0 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_CoreStorage 130.7 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Microsoft Basic Data 20.0 GB disk0s4

/dev/disk1

#: TYPE NAME SIZE IDENTIFIER

0: Apple_HFS Macintosh HD *130.3 GB disk1

Logical Volume on disk0s2

D1498301-E94E-48FF-B819-BF4B24BDAE9C

Unlocked Encrypted

diskutil cs list

sudo fdisk /dev/rdisk0s4

Disk: /dev/disk0 geometry: 30515/255/63 [490234752 sectors]

Signature: 0xAA55

Starting Ending

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

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

1: EE 1023 254 63 - 1023 254 63 [ 1 - 409639] <Unknown ID>

2: AC 1023 254 63 - 1023 254 63 [ 409640 - 255259680] <Unknown ID>

3: AB 1023 254 63 - 1023 254 63 [ 255669320 - 1269536] Darwin Boot

*4: 07 1023 254 63 - 1023 254 63 [ 451172352 - 39061504] HPFS/QNX/AUX

sudo gpt -vv -r show /dev/disk0

gpt show: /dev/disk0: mediasize=251000193024; sectorsize=512; blocks=490234752

gpt show: /dev/disk0: Suspicious MBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 490234751

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 255259680 2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC

255669320 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

256938856 194233496

451172352 39061504 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

490233856 863

490234719 32 Sec GPT table

490234751 1 Sec GPT header

sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C

But after this step, instead of obtaining the first row with NFTS files, I got the following:

Manuels-MacBook-Pro:~ manuelgomes$ sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C

00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|

*

00000200

Does that mean that all is lost??

Could you please elucidate me whether it is possible to recover the data I had in the bootcamp partition and what should be the next steps?

Many thanks,

Manny

1. Please start a new thread, it would keep it succinct.

2. You have the same Yosemite malady that many others have had. For example see Bootcamp win8.1 autorepair fail after yosemite upgrade. If you are comfortable following this it will make the recovery faster. You will need Testdisk and GPT Fdisk. Skip the MBR update part, because it was a simple test which based on your situation will not work anyway.

3. The gap between GPT#3 and GPT#4 is actually a good sign that a recovery is possible.

Okay, have create a new thread atBootcamp disappeared after Yosemite upgrade

I followed your steps as a fall back because following another guide only ended in the "GTP / MRB" discrepancy while choosing a partition to instal windows.

Problem is I don't have a choice to select my USB at startup. I have my OSX drive, a 10.10 restore drive, my extra TB drive, and BOOT EFI. That's it - no windows USB.

Run away from Yosemite I am having so many headache because I upgraded

You can copy the Boot Camp Assistant from your friend and sent to your email, open the content of Boot Camp Assistant then your copy the Info.plist pass it to your break one, then it works.