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Thread: can't boot to Windows 8 after Ubuntu installation

  1. #1
    Join Date
    Dec 2008
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    can't boot to Windows 8 after Ubuntu installation

    I just bought a a Samsung series 5 Ultra laptop (NP520U4C-A01UB). I was able to disable the secure boot feature in the bios and install Ubuntu 12.04 (as dual boot with Windows eight). Ubuntu works fine, but I can't boot to Windows in Grub. I get the following messages:

    Code:
    error: unknown command 'drivemap'
    error: invalid EFI filepath
    Does anyone know how to fix or work around this?
    Last edited by parminides; November 18th, 2012 at 04:03 PM. Reason: added tags

  2. #2
    Join Date
    Nov 2009
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    Segur De Calafell, Spain
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    11,660
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    Ubuntu 12.04 Precise Pangolin

    Re: can't boot to Windows 8 after Ubuntu installation

    Did you install ubuntu in uefi mode or the older legacy mode?

    With uefi boot you actually don't use grub as far as I know. You use the uefi bootloader.

    But you have to make sure you install ubuntu in uefi mode, in other words boot the ubuntu cd/usb as uefi device, not as standard bios device.
    Darko.
    -----------------------------------------------------------------------
    Ubuntu 12.04 LTS 64bit & Windows 7 Ultimate 64bit

  3. #3
    Join Date
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    Chicago Suburbs
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    Ubuntu 14.04 Trusty Tahr

    Re: can't boot to Windows 8 after Ubuntu installation

    If you are booting in UEFI mode, grub-efi has a bug and finds the Windows install, but thinks it still is a BIOS install and creates an incorrect BIOS boot when it should be an efi chain boot entry.

    grub-update fails to detect windows bootloader on a uefi system
    https://bugs.launchpad.net/ubuntu/+s...b2/+bug/807801
    Wrong style chain boot entry
    https://bugs.launchpad.net/ubuntu/+s...2/+bug/1024383


    You can use Boot-Repair to automatically create the correct entry (or convert from BIOS Ubuntu boot to UEFI boot) or manually add a UEFI chain load entry.

    You can just install into your current Ubuntu, use liveCD or USB or download a full repairCD.
    Boot Repair -Also handles LVM, GPT, separate /boot and UEFI dual boot.:
    https://help.ubuntu.com/community/Boot-Repair
    You can repair many boot issues with this or 'Create BootInfo' report (Other Options) & post the link it creates, so we can see your exact configuration and diagnose advanced problems.Install in Ubuntu liveCD or USB or:
    Full RepairCD with Boot-Repair (for newer computers)
    https://help.ubuntu.com/community/UbuntuSecureRemix


    Code:
    menuentry "Windows 7 UEFI" {
      search --file --no-floppy --set=root /efi/Microsoft/Boot/bootmgfw.efi
      chainloader (${root})/efi/Microsoft/Boot/bootmgfw.efi
    }
    So grub does not add the incorrect entries (you can turn on if reconfiguring in the future with other systems).
    In /etc/default/grub I added this:
    gksudo gedit /etc/default/grub
    GRUB_DISABLE_OS_PROBER=true
    or turn off executeable bit
    sudo chmod a-x /etc/grub.d/30_os-prober


    Copy above entry into 40_custom:
    gksudo gedit /etc/grub.d/40_custom
    Then do:
    sudo update-grub
    For info on UEFI boot install & repair:
    http://ubuntuforums.org/showthread.php?t=2147295
    Please use Thread Tools above first post to close thread when/if answered completely.







  4. #4
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    Dec 2008
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    Re: can't boot to Windows 8 after Ubuntu installation

    I don't know if I installed in uefi or legacy mode. I did what old fred suggested and it worked. Thank you so much.

    Specifically, I booted up to an Ubuntu 12.04.1 liveCD and opened a terminal. Then,

    Code:
    sudo add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get update
    sudo apt-get install -y boot-repair && boot-repair
    In boot-repair, I did the recommended repair. When it finished, it gave me the url http://paste.ubuntu.com/1369049/.

    There were two new entries in the grub menu,

    Code:
    Windows UEFI loader
    Windows Boot UEFI boot64.efi
    which both booted to Windows 8.

    The old entries were still in grub,

    Code:
    Windows 8 (loader) (on /dev/sda2)
    Windows Recovery Environment (loader) (on /dev/sda6)
    and they still don't work. I can get to the recovery option with the F4 key after powering up, so I'm going to mark the thread solved. But it would be nice to have recovery mode as a grub option if there's an easy fix.

  5. #5
    Join Date
    Jul 2012
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    Re: can't boot to Windows 8 after Ubuntu installation

    I tried fix this issue all the week on many forums, but this one is the only post that fix my problem. Thank you so much oldfred
    Last edited by diesousil; April 1st, 2013 at 12:54 PM. Reason: Greeting

  6. #6
    Join Date
    May 2013
    Beans
    2

    Re: can't boot to Windows 8 after Ubuntu installation

    Hello,
    please I have the some prob, and i used boot reapir to fix the prob,
    Now I can access to ubuntu (13.04) but windows 8 no!
    this is repprt url of boot repair : http://paste.ubuntu.com/5688390/
    I have Asus k56c
    thanks

  7. #7
    Join Date
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    Chicago Suburbs
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    Ubuntu 14.04 Trusty Tahr

    Re: can't boot to Windows 8 after Ubuntu installation

    Boot-Repair will not fix internal Windows issues.

    It looks like you have installed EasyBCD. It supposedly was updated to work with UEFI. But you should not need it.

    Did you turn off hibernatiion in Windows?

    Boot-Repair renames the Windows boot file and makes shim be the Windows boot file as many UEFI systems are modified to only boot the Windows efi file. But from grub you should be able to boot Windows. The UEFI menu may only boot the renamed shim.

    You have done this. Not sure if you have to or not but second run of Boot-Repair does the rename.
    Boot-Repair - Updated Jan 1, 2013 to not rename first time, but rename if first time Windows does not boot. Post 706 and 711
    http://ubuntuforums.org/showthread.p...769482&page=71
    Boot-Repair copied /EFI/ubuntu/grubx64.efi to /EFI/Boot/bootx64.efi (in case the BIOS is hard-coded to boot into /EFI/Boot/bootx64.efi or secure boot signed GRUB file shimx64.efi.
    Renamed files:
    /EFI/Boot/bkpbootx64.efi
    /EFI/Microsoft/Boot/bkpbootmgfw.efi

    You can unrename and see if Windows boots from UEFI/BIOS directly. And you may be able to run Windows fixes.

    To undo & to rename files to their original names, you just need to tick the "Restore EFI backups" option of Boot-Repair.
    A user disabled secure boot, and unchecked it in boot-repair. It now bypasses Grub and goes straight in to Windows.

    Or

    Windows UEFI install should have backup of bootmgfw.efi here:
    C:\Windows\Boot\EFI\bootmgfw.efi from a working Windows x86_64 installation.

    But if yours is one that only boots Windows efi file you will have to rename again.
    For info on UEFI boot install & repair:
    http://ubuntuforums.org/showthread.php?t=2147295
    Please use Thread Tools above first post to close thread when/if answered completely.







  8. #8
    Join Date
    May 2013
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    2

    Re: can't boot to Windows 8 after Ubuntu installation

    Tanks Oldfred,
    Yes I have installed EasyBCD,
    on booting, if I chose windows 8, it show me this message : error file 'efi/EFI/Boot/bkpbootx64.efi' not found.
    however I checked that this file exist.

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