Grub don't find Windows/EFI

team_Dragon · 2026-01-27 17:33:22

I installed Grub and os-proper and deactiveted os-proper in the "config"file but grub doesn't show Windows
I have an m2 with Windows and an SATA with Arch

5hridhyan · 2026-01-27 17:36:53

did you regenerate grub after?

sudo grub-mkconfig -o /boot/grub/grub.cfg

edit:
if it didn't help please share your output of

cat /etc/default/grub

pacman -Qs os-prober

ls /sys/firmware/efi

is it actually mounted? run "lsblk -f" to see if it is or share that output too, if it is detected and I assume it is not encrypted/BitLocker then mount it and try again.

Last edited by 5hridhyan (2026-01-27 18:00:39)

team_Dragon · 2026-01-27 18:15:25

cat /etc/default/grub:
GRUB_DEFAULT=0
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="Arch"
GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3 quiet"
GRUB_CMDLINE_LINUX=""

# Preload both GPT and MBR modules so that they are not missed
GRUB_PRELOAD_MODULES="part_gpt part_msdos"

# Uncomment to enable booting from LUKS encrypted devices
#GRUB_ENABLE_CRYPTODISK=y

# Set to 'countdown' or 'hidden' to change timeout behavior,
# press ESC key to display menu.
GRUB_TIMEOUT_STYLE=menu

# Uncomment to use basic console
GRUB_TERMINAL_INPUT=console

# Uncomment to disable graphical terminal
#GRUB_TERMINAL_OUTPUT=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 `videoinfo'
GRUB_GFXMODE=auto

# Uncomment to allow the kernel use the same resolution used by grub
GRUB_GFXPAYLOAD_LINUX=keep

# Uncomment if you want GRUB to pass to the Linux kernel the old parameter
# format "root=/dev/xxx" instead of "root=/dev/disk/by-uuid/xxx"
#GRUB_DISABLE_LINUX_UUID=true

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

# Uncomment and set to the desired menu colors. Used by normal and wallpaper
# modes only. Entries specified as foreground/background.
#GRUB_COLOR_NORMAL="light-blue/black"
#GRUB_COLOR_HIGHLIGHT="light-cyan/blue"

# Uncomment one of them for the gfx desired, a image background or a gfxtheme
#GRUB_BACKGROUND="/path/to/wallpaper"
GRUB_THEME="/usr/share/grub/themes/catppuccin-machiato-grub-theme/theme.txt"

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

# Uncomment to make GRUB remember the last selection. This requires
# setting 'GRUB_DEFAULT=saved' above.
#GRUB_SAVEDEFAULT=true

# Uncomment to disable submenus in boot menu
#GRUB_DISABLE_SUBMENU=y

# Probing for other operating systems is disabled for security reasons. Read
# documentation on GRUB_DISABLE_OS_PROBER, if still want to enable this
# functionality install os-prober and uncomment to detect and include other
# operating systems.
GRUB_DISABLE_OS_PROBER=false

pacman -Qs os-prober:
local/os-prober 1.83-1
Utility to detect other OSes on a set of drives

ls /sys/firmware/efi:
ls: Zugriff auf '/sys/firmware/efi' nicht möglich: Datei oder Verzeichnis nicht gefunden

lsblk -f:
NAME FSTYPE FSVER LABEL UUID FSAVAIL FSUSE% MOUNTPOINTS
sda
├─sda1
│ vfat FAT32 49A4-C498 952,3M 7% /boot
└─sda2
btrfs 798f17d7-abfb-4a6e-a866-0cb0f5204a4a 208,8G 5% /home
/var/cache/pacman/pkg
/var/log
/
zram0
swap 1 zram0 22bcce70-b9ea-4400-8a7a-951f1c7fa27c [SWAP]
nvme0n1
│
├─nvme0n1p1
│ vfat FAT32 6EEF-9E9C 146,9M 25% /boot/efi
├─nvme0n1p2
│
├─nvme0n1p3
│ BitLoc 2 PC-ANDRE C: 23.10.2025 495c9415-549c-467b-9022-a62af18e07aa
└─nvme0n1p4
ntfs B6800BF2800BB83F

5hridhyan · 2026-01-27 18:44:33

ls /sys/firmware/efi:
ls: Zugriff auf '/sys/firmware/efi' nicht möglich: Datei oder Verzeichnis nicht gefunden

idk but I assume it showed smtg like "no such file or directory"; so you booted with "legacy boot"; not UEFI/BIOS, disable "legacy boot" or "CSM" and boot the PC in normal UEFI/BIOS
Note: If you installed Arch specifically for BIOS, you must need to re-install the GRUB bootloader specifically for EFI mode once you've booted into a UEFI environment.
in short you may not boot to arch now and it's okay, we have to fix grub
https://wiki.archlinux.org/title/GRUB
boot from live ISO.

before that

├─nvme0n1p3
│ BitLoc 2 PC-ANDRE C: 23.10.2025 495c9415-549c-467b-9022-a62af18e07aa

as I suspected, boot to Windows, yes via BIOS and select Windows Boot Manager manually to boot, Disable BitLocker aka encryption of Windows.
edit:
added "bold" format for that line so future readers might actually
striped out my possible loud thinkings.

Last edited by 5hridhyan (2026-02-02 18:49:34)

team_Dragon · 2026-01-29 13:59:58

After o deactivated both(csm and bitlocker) my BIOS don’t find my SATA disk witch Arch

5hridhyan · 2026-01-29 14:14:47

I did warned about that!,

5hridhyan wrote:

Note: If you installed Arch specifically for BIOS, you must need to re-install the GRUB bootloader specifically for EFI mode once you've booted into a UEFI environment.
in short you may not boot to arch now and it's okay, we have to fix grub
https://wiki.archlinux.org/title/GRUB
boot from live ISO.

ntg is really broken rn, you do have to re-install grub for efi!, also thanks for following up about disabling BitLocker

here is a ToDo list

-as you said CSM is disabled, good, I assume you reported back from Windows or a working system, read this https://wiki.archlinux.org/title/GRUB first, You have to boot to live iso (ArchLinux Live USB/ISO) then mount your partitions,chroot your system, install grub, regenerate it again, and it should detect the drive and boot to arch, also your "Windows" also should show in list.

edit:
tried to help OP by re-clarifying things.

Last edited by 5hridhyan (2026-01-29 16:17:12)

Arch Linux

#1 2026-01-27 17:33:22

Grub don't find Windows/EFI

#2 2026-01-27 17:36:53

Re: Grub don't find Windows/EFI

#3 2026-01-27 18:15:25

Re: Grub don't find Windows/EFI

#4 2026-01-27 18:44:33

Re: Grub don't find Windows/EFI

#5 2026-01-29 13:59:58

Re: Grub don't find Windows/EFI

#6 2026-01-29 14:14:47

Re: Grub don't find Windows/EFI

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