tomfromvleuten
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Q: windows boot option is suddenly missing

Hi, two or three ago suddenly the boot option for Windows has disappeared. It is an Imac 27 inch, late 2013 model on OS X Yosemite 10.10.3 (14D136)

No i can only start OSX and it seems that windows was never there? How can i restore this? I normaly press ALT and then two boot options show up, recently only OSX. I did not changed anything. What i did see in the deleted items is a couple of files since the last days, maybe this is related?

Schermafbeelding 2015-07-01 om 00.01.02.png

 

Modelnaam: iMac

  Modelaanduiding: iMac14,2

  Processornaam: Intel Core i7

  Processorsnelheid: 3,5 GHz

  Aantal processors: 1

  Totale aantal cores: 4

  L2-cache (per core): 256 KB

  L3-cache: 8 MB

  Geheugen: 16 GB

  Opstart-ROM-versie: IM142.0118.B09

  SMC-versie (systeem): 2.15f7

iMac, OS X Yosemite (10.10.3)

Posted on Jun 30, 2015 3:06 PM

by Loner T,Solvedanswer
Loner T Loner T
Level 7 (24,855 points)
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A:

Was the Yosemite Recovery Update applied to your iMac?

Posted on Jun 30, 2015 4:13 PM

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tomfromvleuten

Q: windows boot option is suddenly missing

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  • by tomfromvleuten,

    tomfromvleuten tomfromvleuten Jul 5, 2015 9:44 AM in response to Loner T
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    Jul 5, 2015 9:44 AM in response to Loner T

    Hi, i am sorry but i dont understand? Main menu? were is it? is it what the pictures shows, i dont see expert menu? thanksSchermafbeelding 2015-07-05 om 18.43.03.png

  • by Loner T,

    Loner T Loner T Jul 5, 2015 10:55 AM in response to tomfromvleuten
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    Jul 5, 2015 10:55 AM in response to tomfromvleuten

    Please see the following sequence and note the highlighted information, to change the alignment, before you start creating/deleting partitions.

     

    sudo gdisk /dev/disk0

    GPT fdisk (gdisk) version 1.0.0

     

    Warning: Devices opened with shared lock will not have their

    partition table automatically reloaded!

    Partition table scan:

      MBR: hybrid

      BSD: not present

      APM: not present

      GPT: present

     

    Found valid GPT with hybrid MBR; using GPT.

     

    Command (? for help): p

    Disk /dev/disk0: 500118192 sectors, 238.5 GiB

    Logical sector size: 512 bytes

    Disk identifier (GUID): 22749ACF-207D-458E-B255-5DF02C39DC2D

    Partition table holds up to 128 entries

    First usable sector is 34, last usable sector is 500118158

    Partitions will be aligned on 8-sector boundaries

    Total free space is 1325 sectors (662.5 KiB)

     

    Number  Start (sector)    End (sector)  Size       Code  Name

       1              40          409639   200.0 MiB   EF00  EFI System Partition

       2          409640       250801735   119.4 GiB   AF05  OSY-MBP13

       3       250801736       252071271   619.9 MiB   AB00  Recovery HD

       4       252071936       500117503   118.3 GiB   0700  BOOTCAMP

     

    Command (? for help): x

     

    Expert command (? for help): l

    Enter the sector alignment value (1-65536, default = 2048): 1

     

    Expert command (? for help): p

    Disk /dev/disk0: 500118192 sectors, 238.5 GiB

    Logical sector size: 512 bytes

    Disk identifier (GUID): 22749ACF-207D-458E-B255-5DF02C39DC2D

    Partition table holds up to 128 entries

    First usable sector is 34, last usable sector is 500118158

    Partitions will be aligned on 1-sector boundaries

    Total free space is 1325 sectors (662.5 KiB)

     

    Number  Start (sector)    End (sector)  Size       Code  Name

       1              40          409639   200.0 MiB   EF00  EFI System Partition

       2          409640       250801735   119.4 GiB   AF05  OSY-MBP13

       3       250801736       252071271   619.9 MiB   AB00  Recovery HD

       4       252071936       500117503   118.3 GiB   0700  BOOTCAMP

     

    Continue with bullet/step 3 after these steps.

  • by tomfromvleuten,

    tomfromvleuten tomfromvleuten Jul 6, 2015 12:20 PM in response to Loner T
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    Jul 6, 2015 12:20 PM in response to Loner T

    Hi, i am sorry, but i think i do wrong, i can not continue with step 3....

    Schermafbeelding 2015-07-06 om 21.19.31.png

  • by Loner T,

    Loner T Loner T Jul 6, 2015 12:56 PM in response to tomfromvleuten
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    Jul 6, 2015 12:56 PM in response to tomfromvleuten

    Type 'm' to get back to main menu of Gdisk and then continue.

  • by tomfromvleuten,

    tomfromvleuten tomfromvleuten Jul 6, 2015 1:22 PM in response to Loner T
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    Jul 6, 2015 1:22 PM in response to Loner T

    It doesnt take step 10, which we already changed somewere in the proces "Start again and change step 10 to 1659286407 (one sector before the start of Recovery HD), this will avoid overlapping partitions and run the Gdisk steps and test." Schermafbeelding 2015-07-06 om 22.19.41.png

  • by Loner T,

    Loner T Loner T Jul 6, 2015 1:37 PM in response to tomfromvleuten
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    Jul 6, 2015 1:37 PM in response to tomfromvleuten

    You are on disk0 (SSD), not disk1(HDD). Your Windows should be on disk1. 'q' from this session.

     

    Start with sudo disk /dev/disk1

    x

    l

    1

    m

    d

    2

    d

    3

    ....

  • by tomfromvleuten,

    tomfromvleuten tomfromvleuten Jul 7, 2015 11:41 AM in response to Loner T
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    Jul 7, 2015 11:41 AM in response to Loner T

    Hi, i think i was very precise  on your instruction but i can not go behind step 20?? What i do wrong this time...... :-(

    Schermafbeelding 2015-07-07 om 20.39.35.png

  • by Loner T,

    Loner T Loner T Jul 7, 2015 12:10 PM in response to tomfromvleuten
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    Jul 7, 2015 12:10 PM in response to tomfromvleuten

    Please use 1953525134 as the last sector, since that is the limit of the disk. You do not want to use anything larger, otherwise it will overwrite your secondary GPT table entries.

  • by tomfromvleuten,

    tomfromvleuten tomfromvleuten Jul 7, 2015 12:16 PM in response to Loner T
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    Jul 7, 2015 12:16 PM in response to Loner T

    Before I proceed, this is an overview of the input. Hopefully when i press Y successfulSchermafbeelding 2015-07-07 om 21.14.13.png....

  • by Loner T,

    Loner T Loner T Jul 7, 2015 12:22 PM in response to tomfromvleuten
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    Jul 7, 2015 12:22 PM in response to tomfromvleuten

    After you say 'y', please reboot. After Reboot, please post the output of

     

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

     

    If it does not reboot properly, please use the external OSX installation to boot from. We can then analyze the internal disk partitions.

  • by tomfromvleuten,

    tomfromvleuten tomfromvleuten Jul 7, 2015 12:27 PM in response to Loner T
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    Jul 7, 2015 12:27 PM in response to Loner T

    it didn't boot :-( I tried sudo dd if=/dev/rdisk0s4 count=1 2>/dev/null | hexdump -C but no result ?? Schermafbeelding 2015-07-07 om 12.26.24.png

  • by Loner T,

    Loner T Loner T Jul 7, 2015 12:30 PM in response to tomfromvleuten
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    Jul 7, 2015 12:30 PM in response to tomfromvleuten

    can you post the output of diskutil list? OSX will renumber disks. This is to get the current disk number from which the HDD partition table can be examined.

  • by tomfromvleuten,

    tomfromvleuten tomfromvleuten Jul 7, 2015 12:35 PM in response to Loner T
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    Jul 7, 2015 12:35 PM in response to Loner T

    Schermafbeelding 2015-07-07 om 12.34.15.png

  • by Loner T,

    Loner T Loner T Jul 7, 2015 12:47 PM in response to tomfromvleuten
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    Jul 7, 2015 12:47 PM in response to tomfromvleuten

    Please post  the output of

     

    sudo dd if=/dev/rdisk1s4 count=1 2>/dev/null | hexdump -C

  • by tomfromvleuten,

    tomfromvleuten tomfromvleuten Jul 7, 2015 12:48 PM in response to Loner T
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    Jul 7, 2015 12:48 PM in response to Loner T

    Schermafbeelding 2015-07-07 om 12.48.07.png

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