#Windows Boot Manager not appearing as an option on Grub

34 messages · Page 1 of 1 (latest)

gusty grotto
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I have tried uncommenting GRUB_DISABLE_OS_PROBER=false, I have tried running update-grub.
running os-prober returns nothing but efibootmgr returns the following:

Timeout: 1 seconds
BootOrder: 0000,0004
Boot0000* Ubuntu    HD(2,MBR,0xc3bfcc25,0x2e308800,0x100800)/File(\EFI\UBUNTU\SHIMX64.EFI)
Boot0004* Windows Boot Manager    HD(2,MBR,0xd258ff33,0x7460c000,0xf9800)/File(\EFI\MICROSOFT\BOOT\BOOTMGFW.EFI)0000424f

so i'm not sure why it's not detected by os-prober
also, the windows partition is mounted.
The windows and mint partitions are on separate disks

oblique raft
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do inxi -M in linux to see bios mode also

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or df -h

oblique raft
oblique raft
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if both Windows and Linux are in the same mode, then you can show us the result of :
(maximize terminal first)
cat /etc/default/grub

gusty grotto
# 
# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=menu
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`( . /etc/os-release; echo ${NAME:-Ubuntu} ) 2>/dev/null || echo Ubuntu`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# If your computer has multiple operating systems installed, then you
# probably want to run os-prober. However, if your computer is a host
# for guest OSes installed via LVM or raw disk devices, running
# os-prober can cause damage to those guest OSes as it mounts
# filesystems to look for things.
GRUB_DISABLE_OS_PROBER=false

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"
#

^grub

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checked just in case and my bios mode on windows is uefi too

oblique raft
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so now in linux, simply do sudo update-grub very carefully watch its progress

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it should show it found and added Windows entry

gusty grotto
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as well as 100 times after
it doesnt find windows...

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update-grub output:
```Sourcing file /etc/default/grub' Sourcing file /etc/default/grub.d/50_linuxmint.cfg'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-6.14.0-37-generic
Found initrd image: /boot/initrd.img-6.14.0-37-generic
Found linux image: /boot/vmlinuz-6.14.0-29-generic
Found initrd image: /boot/initrd.img-6.14.0-29-generic
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Adding boot menu entry for UEFI Firmware Settings ...
done

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and as mentioned in the OP running sudo os-prober returns nothing which as far as i understand means it doesnt find any other os's

oblique raft
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ok, see if Disks app can both see and let you access the Windows drive. both its main and EFI partition

gusty grotto
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Both are mounted too i have them set to mount on boot

haughty dirge
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Looks like Windows is MBR boot, Linux is EFI boot. The twain shall never meet.

oblique raft
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that's what has me puzzled.

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only other thing is install rEFInd and use that as your EFI menu selector.

haughty dirge
# oblique raft that's what has me puzzled.

It's rather simple. You can dual boot MBR/MBR or EFI/EFI. Windows has some additional restrictions. If the configuration does not match either, you need to reinstall both operating systems.
The only winning move is not to dual boot.

oblique raft
haughty dirge
oblique raft
haughty dirge
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If it is not detected, something is wrong with the partition or EFI structure. The solution is not tinkering, but creating a new configuration, i.e. reinstalling both with controlled settings. Everything else is wasting lifetime.

gusty grotto
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theyre both in uefi mode 😭

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i already reinstalled mint cuz i had a different problem but in the original installation that part worked

oblique raft
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just use your machine's boot menu key to choose you SECOND-favourite OS, when needed. it's not that hard.

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or refind

gusty grotto
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I will, i just like to fix things