Arch Linux

Habib_Du

Member

Registered: 2025-04-02

Posts: 3

windows 10 is not in Grub menu

Hello
since i reinstalled windows 10 after arch it was not in the grub menu. to open windows i have to open the bios and boot into windows and i tried some methods to fix it like : turning off fast boot on windows , checking if it was detected by Grub ( sudo os-proberand ) it was indeed, i checked if os-prober is disabled but it wasn't, and i checked if the Windows partition exists.

this is the output of sudo os-proberand just in case i missed something.

/dev/nvme0n1p1@/EFI/Microsoft/Boot/bootmgfw.efi:Windows Boot Manager:Windows:efi
/usr/lib/os-probes/50mounted-tests: line 72:  2406 Segmentation fault      (core dumped) grub-mount "$partition" "$tmpmnt" 2> /dev/null
/usr/lib/os-probes/50mounted-tests: line 72:  2455 Segmentation fault      (core dumped) grub-mount "$partition" "$tmpmnt" 2> /dev/null.

and this is the output of sudo fdisk -l.

Disk /dev/nvme0n1: 953.87 GiB, 1024209543168 bytes, 2000409264 sectors
Disk model: YSSDHB-1TN7000                          
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 5BCB4A1F-18F0-47AA-880A-B5C4526698F8

Device              Start        End    Sectors   Size Type
/dev/nvme0n1p1       2048    2099199    2097152     1G EFI System
/dev/nvme0n1p2    2099200   69208063   67108864    32G Linux swap
/dev/nvme0n1p3   69208064 1327499263 1258291200   600G Linux root (x86-64)
/dev/nvme0n1p4 1327499264 1327532031      32768    16M Microsoft reserved
/dev/nvme0n1p5 1327532032 2000408575  672876544 320.9G Microsoft basic data.

i still don't know where the problem is coming from i would really appreciate any help to fix this issue

Last edited by Habib_Du (2025-04-02 07:24:38)

mackin_cheese

Member

Registered: 2025-01-07

Posts: 477

Re: windows 10 is not in Grub menu

You stated that you checked if it was probing by grub but you never stated if you generated a new grub config. Did you generate a new config via grub-mkconfig?

cryptearth

Member

Registered: 2024-02-03

Posts: 2,119

Re: windows 10 is not in Grub menu

the problem is the current version of grub 2.12.rSomething
revert back to stable 2.12 should fix this and also shoukd get rid of those segfaults - there's an entire topic about that issue

also: using the bios boot menu is how uefi is actually designed and to be used - its grub which still is more a boot manager than a simple boot loader - but so are pretty much all so called boot loaders
the exception which come the most close to a pure boot loader is using efi-stub / uki

Habib_Du

Member

Registered: 2025-04-02

Posts: 3

Re: windows 10 is not in Grub menu

i installed grub as a fresh install and i did not manipulate with its files so i Did not generate a new config via grub-mkconfig and i dont know how to do that.
and i have just downgraded grub to 2.12-3 using downgrade command but Unfortunately it did not work

Habib_Du

Member

Registered: 2025-04-02

Posts: 3

Re: windows 10 is not in Grub menu

update : the problem was that i did not generate a new config so i ran the command "sudo grub-mkconfig -o /boot/grub/grub.cfg" that should regenerate the GRUB configuration. thanks for the help