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Level 1

8 points

Cannot boot OS X, only Windows, no recovery.

I have a brand new MacBook Air 11 with Yosemite, and with BootCamp 5 we have installed Windows 7 (on a partition with some 320 GB). Our IT has managed to install Windows 7 Enterprise 64 and has installed a lot of company software. It is the same setting as with my previous MacBook Air, which did work properly for years with bootcamp.

The actual problem: When starting with Option key, I only can see Windows, no OS X and not even the recovery OS.

In Windows computer management I can see partitions with 200 MB (GPT), 150 GB (primary partition, no name), 100 MB NTFS (active, primary partition) and finally 320 GB NTFS (start partition) for Windows.

I have zapped PRAM, have tried to start with S key, X and many more.

When I start with Option R and boot the online recovery system, with disk utility I can see the MacBook SSD (500 GB), therein is a volume (an active logical partition) with 160 GB, a mount point, format "Logical partition", 19 GB in use (which might be Mac OS X and some files) as well as a disk0s4 with 340 GB (not active)

I have repaired access rights and checked volume, no errors.

For me it looks if all partitions are here and even OS X is still installed, but boot manager only provides Windows to start with.

I really would like to avoid installing from scratch again since this will last for days again.

What can I do? Should I try to reinstall OS X on that partition, hoping that the (company) Windows still will work?

Many thanks!

Posted on Jan 15, 2015 9:23 PM

27 replies

Loner T

Level 9

59,471 points

Jan 20, 2015 7:39 AM in response to lgb-wien

Please ignore the following message and continue.

fdisk: could not open MBR file /usr/standalone/i386/boot0: No such file or directory

lgb-wien Author

Level 1

8 points

Jan 20, 2015 8:04 AM in response to Loner T

Klauss-MacBook-Air:~ Klaus$ sudo fdisk -e /dev/disk0

fdisk: could not open MBR file /usr/standalone/i386/boot0: No such file or directory

Enter 'help' for information

fdisk: 1> p

Disk: /dev/disk0 geometry: 60821/255/63 [977105060 sectors]

Offset: 0 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 - 311363320] <Unknown ID>

3: AB 1023 254 63 - 1023 254 63 [ 311772960 - 1269536] Darwin Boot

4: 0C 1023 254 63 - 1023 254 63 [ 313042944 - 664061952] Win95 FAT32L

fdisk: 1> setpid 4

Starting Ending

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

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

4: 0C 1023 254 63 - 1023 254 63 [ 313042944 - 664061952] Win95 FAT32L

Partition id ('0' to disable) [0 - FF]: [C] (? for help) 07

fdisk:*1> flag 4

Partition 4 marked active.

fdisk:*1> p

Disk: /dev/disk0 geometry: 60821/255/63 [977105060 sectors]

Offset: 0 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 - 311363320] <Unknown ID>

3: AB 1023 254 63 - 1023 254 63 [ 311772960 - 1269536] Darwin Boot

*4: 07 1023 254 63 - 1023 254 63 [ 313042944 - 664061952] HPFS/QNX/AUX

fdisk:*1> w

Device could not be accessed exclusively.

A reboot will be needed for changes to take effect. OK? [n] y

Writing MBR at offset 0.

I make restart now

lgb-wien Author

Level 1

8 points

Jan 20, 2015 8:16 AM in response to lgb-wien

did it and we are getting closer:

With Option at reboot I can select Mac OS X and Windows drive to boot from, but at Windows it only says "Missing operating system ...";

OS X is running, disk utility does show disk0s4 in gray,

mount point: not activated

format: (MS-DOS) FAT

owner activated:-

number of folders: -

capacity: 340 GB

available: -

used: -

number of files: -

It seems, windows is gone.

I could try to restore from a Norton Backup (but maybe miss drivers) or first install Windows 7 there - with the risk that again MBR is changed and OS X is unavailable.

Or better to make use of Boot Camp again for a fresh install?

Many thanks!

Loner T

Level 9

59,471 points

Jan 20, 2015 8:45 AM in response to lgb-wien

Can you post the output of

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

lgb-wien Author

Level 1

8 points

Jan 20, 2015 8:53 AM in response to Loner T

Klauss-Air:~ Klaus$ sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C

Password:

00000000 00 2f 00 00 00 14 00 00 00 30 00 00 00 15 00 00 |./.......0......|

00000010 00 31 00 00 00 15 00 00 00 32 00 00 00 15 00 00 |.1.......2......|

00000020 00 33 00 00 00 15 00 00 00 34 00 00 00 15 00 00 |.3.......4......|

00000030 00 34 00 00 00 15 00 00 00 34 00 00 00 16 00 00 |.4.......4......|

00000040 00 35 00 00 00 16 00 00 00 34 00 00 00 16 00 00 |.5.......4......|

00000050 00 34 00 00 00 16 00 00 00 34 00 00 00 16 00 00 |.4.......4......|

00000060 00 33 00 00 00 17 00 00 00 32 00 00 00 17 00 00 |.3.......2......|

00000070 00 32 00 00 00 17 00 00 00 31 00 00 00 17 00 00 |.2.......1......|

00000080 00 30 00 00 00 17 00 00 00 2f 00 00 00 18 00 00 |.0......./......|

00000090 00 2f 00 00 00 18 00 00 00 2f 00 00 00 19 00 00 |./......./......|

000000a0 00 2f 00 00 00 1a 00 00 00 2f 00 00 00 1a 00 00 |./......./......|

000000b0 00 2f 00 00 00 1b 00 00 00 30 00 00 00 1c 00 00 |./.......0......|

000000c0 00 30 00 00 00 1c 00 00 00 31 00 00 00 1d 00 00 |.0.......1......|

000000d0 00 32 00 00 00 1d 00 00 00 33 00 00 00 1d 00 00 |.2.......3......|

000000e0 00 34 00 00 00 1d 00 00 00 35 00 00 00 1c 00 00 |.4.......5......|

000000f0 00 37 00 00 00 1b 00 00 00 37 00 00 00 1b 00 00 |.7.......7......|

00000100 00 38 00 00 00 1a 00 00 00 39 00 00 00 1a 00 00 |.8.......9......|

00000110 00 39 00 00 00 19 00 00 00 3a 00 00 00 19 00 00 |.9.......:......|

00000120 00 3a 00 00 00 19 00 00 00 39 00 00 00 19 00 00 |.:.......9......|

00000130 00 39 00 00 00 19 00 00 00 38 00 00 00 1a 00 00 |.9.......8......|

00000140 00 38 00 00 00 1a 00 00 00 37 00 00 00 1b 00 00 |.8.......7......|

00000150 00 36 00 00 00 1c 00 00 00 35 00 00 00 1d 00 00 |.6.......5......|

00000160 00 34 00 00 00 1e 00 00 00 33 00 00 00 1f 00 00 |.4.......3......|

00000170 00 32 00 00 00 20 00 00 00 32 00 00 00 22 00 00 |.2... ...2..."..|

00000180 00 31 00 00 00 23 00 00 00 31 00 00 00 24 00 00 |.1...#...1...$..|

00000190 00 30 00 00 00 26 00 00 00 30 00 00 00 27 00 00 |.0...&...0...'..|

000001a0 00 30 00 00 00 27 00 00 00 31 00 00 00 28 00 00 |.0...'...1...(..|

000001b0 00 31 00 00 00 29 00 00 00 31 00 00 00 29 00 00 |.1...)...1...)..|

000001c0 00 32 00 00 00 29 00 00 00 32 00 00 00 2a 00 00 |.2...)...2...*..|

000001d0 00 32 00 00 00 2a 00 00 00 32 00 00 00 2b 00 00 |.2...*...2...+..|

000001e0 00 32 00 00 00 2b 00 00 00 32 00 00 00 2b 00 00 |.2...+...2...+..|

000001f0 00 32 00 00 00 2c 00 00 00 32 00 00 00 2c 00 00 |.2...,...2...,..|

00000200

lgb-wien Author

Level 1

8 points

Jan 20, 2015 8:58 AM in response to lgb-wien

I will try a better screenshot

lgb-wien Author

Level 1

8 points

Jan 20, 2015 8:59 AM in response to lgb-wien

Loner T

Level 9

59,471 points

Jan 20, 2015 9:19 AM in response to lgb-wien

You do not have a NTFS header.

Initially you mentioned

In Windows computer management I can see partitions with 200 MB (GPT), 150 GB (primary partition, no name), 100 MB NTFS (active, primary partition) and finally 320 GB NTFS (start partition) for Windows.

1. Was Windows installed using EFI Boot? The 100MB NTFS indicates such an installation.

2. Where did the following Fdisk come from?

-bash-3.2# fdisk /dev/disk0

Disk: /dev/disk0 geometry: 60821/255/63 [977105060 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 - 311363320] <Unknown ID>

*3: 07 1023 254 63 - 1023 254 63 [ 311773184 - 204800] HPFS/QNX/AUX

4: 07 1023 254 63 - 1023 254 63 [ 311977984 - 665124864] HPFS/QNX/AUX

3. Your current Fdisk output does not show the 100MB NTFS entry, but just EFI/OSX, OSX, Recovery HD and Windows.

Disk: /dev/disk0 geometry: 60821/255/63 [977105060 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 - 311363320] <Unknown ID>

3: AB 1023 254 63 - 1023 254 63 [ 311772960 - 1269536] Darwin Boot

4: 0C 1023 254 63 - 1023 254 63 [ 313042944 - 664061952] Win95 FAT32L

4. Did these two Fdisk outputs come from the same disk?

lgb-wien Author

Level 1

8 points

Jan 20, 2015 9:44 AM in response to Loner T

re 1: I have to check with IT guys from my company about details of EFI/boot (I am no expert at all),

but what I know is: we had several failed attempts installing Windows 7 enterprise via Bootcamp ("best" result was working Windows, but in Windows the bootcamp control panel was missing, so I could not use right click..). Finally IT guys managed to install Windows 7 Pro via Bootcamp and afterwards somehow "migrated" to Win 7 Enterprise, which was working, but OS X was gone. Looks like a "wrong" way of installing.

The hint about NTFS came from Windows with a right click on computer which started computer management app.

re 2-4: all OS X disk answers came from the same 500 GB flash drive in my MacBook Air, but

re 2: the first fdisk was done from online recovery system (command option R at restart), while

3 and 4 were done from (now working) OS X directly.

In case I have to install Windows from scratch with bootcamp, is there any way to install Win 7 Enterprise (which we already did several times in the past, but not on my new MacBook Air)?

Many thanks

Loner T

Level 9

59,471 points

Jan 20, 2015 10:11 AM in response to lgb-wien

Windows Enterprise versions are not supported by Bootcamp. It may explain how Windows Enterprise was installed using an EFI boot.

lgb-wien Author

Level 1

8 points

Jan 20, 2015 11:36 AM in response to Loner T

well, our IT guys have positively installed Win 7 Enterprise on a brand new MacBook Pro (which I am using right now) with bootcamp, where OS X, bootcamp and Windows are working and all 3 systems (OS X, Windows and recovery) can be selected at reboot with Option key. Same for my old MacBook Air with OS X and Win 7 Enterprise.

I think I will return my new MacBook Air to IT to start a new attempt.

Just to understand: EFI boot does mean installation not within bootcamp and this did cause my problems?

Many thanks for all your answers, I really did appreciate and enjoy this support!

Best regards

Klaus

Loner T

Level 9

59,471 points

Jan 20, 2015 12:20 PM in response to lgb-wien

Your first and second Fdisk outputs have conflicting information. The 100MB NTFS partition in the first one and marked bootable in MBR with a second NTFS is very confusing.

The second Fdisk output looks like a standard BC Hybrid MBR.

From Boot Camp 5.1: Frequently asked questions - Apple Support

Which versions of Windows work with Boot Camp 5.1?

Boot Camp 5.1 supports 64-bit, non-Enterprise versions of Windows 7, Windows 8.0, and Windows 8.1. This version of Boot Camp doesn't support Windows XP, Windows Vista, or any 32-bit version of Windows. Depending on your Mac, you may be able to use an earlier version of Boot Camp to work with other versions of Windows. For details, see the Boot Camp system requirements for Microsoft Windows.

Cannot boot OS X, only Windows, no recovery.