MBP always boots in removed windows 7 EFI partition

Question

MBP always boots in removed windows 7 EFI partition

Hi all,

i have a strange issue: after trying desperately to install windows 7 alongside Yosemite on an early 2011 MBP i gave up and deleted the bootcamp partition.

But now it always boots into a windows blue screen of death, even after i make yosemite the startup disk in system preferences.

I always have to start up with the ALT key and am regularly confronted with the blue screen when i forget.

Booting with the ALT key gives me 2 choices: OS X and 'EFI boot'

Windows is haunting me after i deleted it and come to think that i only wanted to try it out because i could. **** you Windows.

It tells me that windows cannot start and it needs repairs, which is obvious because i deleted the windows partition.

Something tells me that it has something to do with the EFI partition where some windows software has to be installed, but disk utility won't let me delete the partition, because it thinks it's the OS X EFI.

Is there a way to restore the EFI partition to a proper OS X partition or how do i delete it and how?

Thanks in advance for your time and effort,

Best of regards,

-sander

Volume layout:

gemeengoed:~ sander$ diskutil list
/dev/disk0
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *250.1 GB   disk0
   1:                  Apple_HFS                         209.7 MB   disk0s1
   2:          Apple_CoreStorage                         249.2 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS ssd 250                *248.8 GB   disk1
                                 Logical Volume on disk0s2
                                 xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
                                 Unlocked Encrypted

MacBook Pro, OS X Yosemite (10.10.1), Early 2011 16GB with HDD in DVD bay

Posted on Nov 23, 2014 12:54 PM

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Answer 1

Loner T

Level 9

59,471 points

Nov 23, 2014 1:37 PM in response to tisseenschande

Please reset NVRAM - Startup key combinations for Intel-based Macs - Apple Support and OS X Mavericks: Reset your computer’s PRAM. You have Bootcamp settings in the nvram that are causing problems.

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Answer 2

Nov 23, 2014 2:34 PM in response to Loner T

tried it and still no go. Have downloaded rEFIt and try and fix it from there. rEFIt analyse gives me this:

thanks for your brain time though.

*** Report for internal hard disk ***

Current GPT partition table:

# Start LBA End LBA Type

1 40 409639 Mac OS X HFS+

2 409640 487127591 Unknown

3 487127592 488397127 Mac OS X Boot

Current MBR partition table:

# A Start LBA End LBA Type

1 1 488397167 ee EFI Protective

MBR contents:

Boot Code: Unknown, but bootable

Partition at LBA 40:

Boot Code: None (Non-system disk message)

File System: FAT32

Listed in GPT as partition 1, type Mac OS X HFS+

Partition at LBA 409640:

Boot Code: None

File System: Unknown

Listed in GPT as partition 2, type Unknown

Partition at LBA 487127592:

Boot Code: None

File System: HFS Extended (HFS+)

Listed in GPT as partition 3, type Mac OS X Boot

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Answer 3

Loner T

Level 9

59,471 points

Nov 23, 2014 3:04 PM in response to tisseenschande

1. To use EFI-based installation, you need to partition via Disk Utility and create a GPT partition.

2. To install using Bootcamp Assistant, you need to let it partition the internal drive. You cannot mix both methods.

3. If you deleted the partition using Disk Utility, but method 2 was used, you have a corrupted MBR (not GPT) that needs to be corrected. The NVRAM may also need to be reset.

4. Please post the output of the following two commands from OSX Terminal to determine the state of your internal disk.

sudo gpt -vv -r show /dev/disk0

sudo fdisk /dev/disk0

These two command show your GPT and MBR. GPT Fdisk reads both GPT and MBR. rEFIt is just confusing the issue you have. The EFI partition can only be restored by initializing the internal disk. I suggest not trying to initialize it. The EFI for OSX and Windows (if using the EFI method) is separate. You diskutil list does not show a Windows EFI partition at all. In your case, did you install rEFIt on the first partition (disk0s1)?

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Answer 4

Nov 23, 2014 4:35 PM in response to Loner T

thanks again guys for your advice. here's my output:

gemeengoed:~ sander$ sudo gpt -vv -r show /dev/disk0
gpt show: /dev/disk0: mediasize=250059350016; sectorsize=512; blocks=488397168
gpt show: /dev/disk0: PMBR at sector 0
gpt show: /dev/disk0: Pri GPT at sector 1
gpt show: /dev/disk0: Sec GPT at sector 488397167
      start       size  index  contents
          0          1         PMBR
          1          1         Pri GPT header
          2         32         Pri GPT table
         34          6
         40     409600      1  GPT part - 48465300-0000-11AA-AA11-00306543ECAC
     409640  486717952      2  GPT part - 53746F72-6167-11AA-AA11-00306543ECAC
  487127592    1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
  488397128          7
  488397135         32         Sec GPT table
  488397167          1         Sec GPT header





gemeengoed:~ sander$ sudo fdisk /dev/disk0
Password:
Disk: /dev/disk0 geometry: 30401/255/63 [488397168 sectors]
Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: EE 1023 254  63 - 1023 254  63 [         1 -  488397167] <Unknown ID>
 2: 00    0   0   0 -    0   0   0 [         0 -          0] unused
 3: 00    0   0   0 -    0   0   0 [         0 -          0] unused
 4: 00    0   0   0 -    0   0   0 [         0 -          0] unused

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Answer 5

Loner T

Level 9

59,471 points

Nov 23, 2014 4:54 PM in response to tisseenschande

Please remove/uninstall rEFIt. Power cycle your Mac and hold the Alt Key. What Options do you see?

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Answer 6

Nov 24, 2014 9:29 AM in response to Loner T

i think i have a quick fix: rebooting with option-R and setting the startup disk from there makes it boot with OS X

That is, until i uninstalled rEFIt and rebooted with ALT, where i have 2 choices: Recovery HD and EFI boot

After selecting Recovery HD and rebooting it defaults to the EFI boot again [and the blue windows 7 screen].

Thanks again for your valuable support,

Cheers,

-sander

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Answer 7

Loner T

Level 9

59,471 points

Nov 24, 2014 11:12 AM in response to tisseenschande

Do you have a good Time Machine backup of OSX, or can you create a new backup using Command+R and boot into OSX and setup TM to do a fresh backup?

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Answer 8

Dec 8, 2014 4:38 PM in response to Loner T

had a few weeks of hard freelance work on another workstation.

no, i do not have a recent timemachine backup. i am throwing the towel in the ring and will back my files up and do a reinstall.

thanks for your time guys. cheers.

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Answer 9

Loner T

Level 9

59,471 points

Dec 8, 2014 5:33 PM in response to tisseenschande

Was rEFInd installed in your EFI partition?

Have you looked at http://www.rodsbooks.com/refind/yosemite.html?

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Answer 10

Dec 9, 2014 11:48 AM in response to Loner T

hi Loner T,

i tried to format the disk but it was busy, seemed it was mounted twice, both as disk0 and as disk3. when i ran diskutil unmount on both disks i was able to format it and i'm in the process of a carbon copy clone from an external drive.

thanks again for your support,

-sander

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