недопустимый путь к файлу EFI на окнах 8.1 рядом с Ubuntu 12.04 LTS

Я установил Ubuntu 12.04 LTS alonside с Windows 8.1 на отдельном logica разделе. Теперь, я могу только войти в Ubuntu. Когда я пытаюсь войти в Windows из меню GRUB, я получаю ошибку, которая приводит меня обратно к меню GRUB. Вот мой cat /boot/grub/grub.cfg:

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  set have_grubenv=true
  load_env
fi
set default="0"
if [ "${prev_saved_entry}" ]; then
  set saved_entry="${prev_saved_entry}"
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z "${boot_once}" ]; then
    saved_entry="${chosen}"
    save_env saved_entry
  fi
}

function recordfail {
  set recordfail=1
  if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}

function load_video {
  insmod efi_gop
  insmod efi_uga
  insmod video_bochs
  insmod video_cirrus
}

insmod part_gpt
insmod ext2
set root='(hd0,gpt5)'
search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
if loadfont /usr/share/grub/unicode.pf2 ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  insmod part_gpt
  insmod ext2
  set root='(hd0,gpt5)'
  search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
  set locale_dir=($root)/boot/grub/locale
  set lang=en_US
  insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ] ; then
  set timeout=-1
else
  set timeout=10
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
if background_color 44,0,30; then
  clear
fi
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
function gfxmode {
    set gfxpayload="${1}"
    if [ "${1}" = "keep" ]; then
        set vt_handoff=vt.handoff=7
    else
        set vt_handoff=
    fi
}
if [ "${recordfail}" != 1 ]; then
  if [ -e ${prefix}/gfxblacklist.txt ]; then
    if hwmatch ${prefix}/gfxblacklist.txt 3; then
      if [ ${match} = 0 ]; then
        set linux_gfx_mode=keep
      else
        set linux_gfx_mode=text
      fi
    else
      set linux_gfx_mode=text
    fi
  else
    set linux_gfx_mode=keep
  fi
else
  set linux_gfx_mode=text
fi
export linux_gfx_mode
if [ "${linux_gfx_mode}" != "text" ]; then load_video; fi
menuentry 'Ubuntu, with Linux 3.11.0-26-generic' --class ubuntu --class gnu-linux --class gnu --class os {
    recordfail
    gfxmode $linux_gfx_mode
    insmod gzio
    insmod part_gpt
    insmod ext2
    set root='(hd0,gpt5)'
    search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
    linux   /boot/vmlinuz-3.11.0-26-generic.efi.signed root=UUID=c6cb0b77-0048-47b5-9b93-6b28c43c4900 ro   quiet splash $vt_handoff
    initrd  /boot/initrd.img-3.11.0-26-generic
}
menuentry 'Ubuntu, with Linux 3.11.0-26-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
    recordfail
    insmod gzio
    insmod part_gpt
    insmod ext2
    set root='(hd0,gpt5)'
    search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
    echo    'Loading Linux 3.11.0-26-generic ...'
    linux   /boot/vmlinuz-3.11.0-26-generic.efi.signed root=UUID=c6cb0b77-0048-47b5-9b93-6b28c43c4900 ro recovery nomodeset 
    echo    'Loading initial ramdisk ...'
    initrd  /boot/initrd.img-3.11.0-26-generic
}
submenu "Previous Linux versions" {
menuentry 'Ubuntu, with Linux 3.11.0-15-generic' --class ubuntu --class gnu-linux --class gnu --class os {
    recordfail
    gfxmode $linux_gfx_mode
    insmod gzio
    insmod part_gpt
    insmod ext2
    set root='(hd0,gpt5)'
    search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
    linux   /boot/vmlinuz-3.11.0-15-generic root=UUID=c6cb0b77-0048-47b5-9b93-6b28c43c4900 ro   quiet splash $vt_handoff
    initrd  /boot/initrd.img-3.11.0-15-generic
}
menuentry 'Ubuntu, with Linux 3.11.0-15-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
    recordfail
    insmod gzio
    insmod part_gpt
    insmod ext2
    set root='(hd0,gpt5)'
    search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
    echo    'Loading Linux 3.11.0-15-generic ...'
    linux   /boot/vmlinuz-3.11.0-15-generic root=UUID=c6cb0b77-0048-47b5-9b93-6b28c43c4900 ro recovery nomodeset 
    echo    'Loading initial ramdisk ...'
    initrd  /boot/initrd.img-3.11.0-15-generic
}
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
    insmod part_gpt
    insmod ext2
    set root='(hd0,gpt5)'
    search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
    linux16 /boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
    insmod part_gpt
    insmod ext2
    set root='(hd0,gpt5)'
    search --no-floppy --fs-uuid --set=root c6cb0b77-0048-47b5-9b93-6b28c43c4900
    linux16 /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Windows 8 (loader) (on /dev/sda4)" --class windows --class os {
    insmod part_gpt
    insmod ntfs
    set root='(hd0,gpt4)'
    search --no-floppy --fs-uuid --set=root BC4254984254596A
    drivemap -s (hd0) ${root}
    chainloader +1
}
set timeout_style=menu
if [ "${timeout}" = 0 ]; then
  set timeout=10
fi
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/30_uefi-firmware ###
menuentry 'System setup' {
    fwsetup
}
### END /etc/grub.d/30_uefi-firmware ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f  $prefix/custom.cfg ]; then
  source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###

Выполнение sudo lsblk -o NAME,FSTYPE,SIZE,MOUNTPOINT,LABEL производит это:

NAME   FSTYPE   SIZE MOUNTPOINT LABEL
sda           931.5G            
├─sda1 ntfs    1023M            Windows RE tools
├─sda2 vfat     360M /boot/efi  SYSTEM
├─sda3          128M            
├─sda4 ntfs   809.3G            OS
├─sda5 ext4    53.5G /          
├─sda6 ntfs     9.6G            Private
├─sda7 ntfs    47.7G            Linux
├─sda8 ntfs     350M            
└─sda9 swap     9.6G [SWAP]     
sr0            1024M