Linux GRUB Not Showing Windows? Proven Solutions (2026)

Linux grub not showing windows is a common issue for dual-boot users. You expect to see both Linux and Windows options in the GRUB menu, but only Linux entries appear.

When linux grub not showing windows occurs, you cannot boot into Windows directly from GRUB. This proven guide provides effective methods to detect Windows and restore the boot entry in your GRUB menu.

1. Root Cause

When linux grub not showing windows occurs, the GRUB bootloader cannot detect the Windows installation. This is usually because the os-prober tool is disabled, not installed, or fails to detect Windows.

Another common cause is boot mode mismatch. If Linux is installed in UEFI mode and Windows is in legacy BIOS mode (or vice versa), GRUB cannot boot the other operating system. This often happens when Windows is installed first in one mode and Linux later in a different mode.

GRUB configuration changes can also cause this issue. Updates to GRUB packages may reset the GRUB_DISABLE_OS_PROBER setting to true. System updates or manual edits to /etc/default/grub can disable OS detection.

Partition table issues, missing Windows boot files, or corrupted boot entries can prevent detection. According to the Arch Linux Wiki, os-prober is essential for detecting other operating systems. The Ubuntu Community Help also highlights boot mode consistency as a key factor.

2. Run os-prober Manually

The simplest fix for linux grub not showing windows is to run os-prober manually. This tool scans all disks for operating systems and reports them to GRUB.

sudo os-prober

If Windows is detected, you will see output like /dev/sda2:Windows 11:Windows:chain. After running os-prober, update GRUB to include the new entry. If os-prober does not detect Windows, proceed to the next methods.

Outcome: Running os-prober manually resolves the linux grub not showing windows issue if detection is successful.

3. Enable os-prober in GRUB Configuration

If os-prober runs but Windows still does not appear, check the GRUB configuration. The GRUB_DISABLE_OS_PROBER setting may be enabled, preventing detection.

sudo nano /etc/default/grub

Find the line GRUB_DISABLE_OS_PROBER=true. Change it to GRUB_DISABLE_OS_PROBER=false. If the line does not exist, add it. Save the file. Then run sudo update-grub to regenerate the configuration.

Outcome: Enabling os-prober resolves the linux grub not showing windows issue caused by disabled OS detection.

4. Update GRUB Configuration

After enabling os-prober, update the GRUB configuration. This command scans for operating systems and generates the boot menu.

sudo update-grub        # Ubuntu, Debian, Linux Mint
sudo grub-mkconfig -o /boot/grub/grub.cfg   # Fedora, Arch, openSUSE

For Ubuntu-based systems, update-grub is a convenient wrapper. For other distributions, use grub-mkconfig. Reboot and check if Windows appears in the GRUB menu.

Outcome: Updating GRUB configuration resolves the linux grub not showing windows issue.

5. Install os-prober if Missing

Some minimal Linux installations do not include os-prober. Installing it can fix linux grub not showing windows.

sudo apt install os-prober        # Debian/Ubuntu
sudo dnf install os-prober         # Fedora
sudo pacman -S os-prober           # Arch

After installation, run sudo os-prober and then sudo update-grub. This ensures GRUB has the tools to detect other operating systems.

Outcome: Installing os-prober resolves the linux grub not showing windows issue if the tool was missing.

6. Check Boot Mode Consistency (UEFI/BIOS)

Boot mode mismatch is a major cause of linux grub not showing windows. Linux and Windows must be installed in the same boot mode (both UEFI or both BIOS).

ls /sys/firmware/efi/efivars   # If exists, system is in UEFI mode
sudo fdisk -l                  # Check partition table type (GPT or MBR)

If Linux is in UEFI mode (efivars exists) but Windows is installed in BIOS mode, GRUB cannot boot Windows. You may need to reinstall one operating system in the matching mode. Check your system’s firmware settings to verify the boot mode for each OS.

Outcome: Ensuring boot mode consistency resolves the linux grub not showing windows issue.

7. Verify Partition Table and Boot Flags

Partition table issues can prevent GRUB from detecting Windows. Verify the Windows partition is correctly set up for booting.

sudo fdisk -l
sudo gdisk -l /dev/sdX   # For GPT disks

Check that the Windows partition has the boot flag (for MBR) or the EFI system partition exists (for UEFI). If the partition table is corrupted, tools like TestDisk can help recover it.

Outcome: Verifying partition table resolves the linux grub not showing windows issue caused by corrupted boot flags.

8. Manually Add Windows Entry to GRUB

If automatic detection fails, manually adding Windows to GRUB can fix linux grub not showing windows. This is a reliable workaround.

sudo nano /etc/grub.d/40_custom

Add the following lines for Windows:

menuentry "Windows 11" {
    insmod chain
    insmod ntfs
    set root=(hd0,1)
    chainloader +1
}

Replace (hd0,1) with the correct partition number. Use sudo fdisk -l to find the Windows partition. After saving, run sudo update-grub.

Outcome: Manually adding Windows entry resolves the linux grub not showing windows issue when automatic detection fails.

9. Reinstall GRUB Bootloader

Reinstalling GRUB can fix linux grub not showing windows by refreshing the bootloader and its configuration.

sudo grub-install /dev/sdX
sudo update-grub

Replace /dev/sdX with the disk device (e.g., /dev/sda). For UEFI systems, use sudo grub-install --target=x86_64-efi --efi-directory=/boot/efi. This reinstalls GRUB and regenerates the configuration.

Outcome: Reinstalling GRUB resolves the linux grub not showing windows issue caused by bootloader corruption.

10. Advanced: Use efibootmgr to Manage UEFI Entries

For UEFI systems, efibootmgr can help manage boot entries. This advanced method can fix linux grub not showing windows by ensuring Windows entry exists.

sudo efibootmgr -v
sudo efibootmgr -c -L "Windows Boot Manager" -l \\EFI\\Microsoft\\Boot\\bootmgfw.efi

List current boot entries with efibootmgr -v. If Windows is missing, add it with the second command. After adding, reboot and check if Windows appears in GRUB.

Outcome: Using efibootmgr resolves the linux grub not showing windows issue on UEFI systems.

11. Frequently Asked Questions

Why is Windows not showing in GRUB?

This can be due to disabled os-prober, boot mode mismatch, missing os-prober package, or partition table issues.

How do I enable os-prober in GRUB?

Edit /etc/default/grub and set GRUB_DISABLE_OS_PROBER=false. Then run sudo update-grub.

What is the os-prober command in Linux?

os-prober scans disks for operating systems. It detects Windows, other Linux distributions, and macOS installations.

Can I manually add Windows to GRUB?

Yes, add a custom entry to /etc/grub.d/40_custom and run sudo update-grub.

What if my system uses UEFI and Windows does not appear?

Check if both systems are in UEFI mode. Use efibootmgr to verify and add the Windows boot entry.

How do I update GRUB on Fedora?

Use sudo grub-mkconfig -o /boot/grub/grub.cfg instead of update-grub.

Why does os-prober not detect Windows?

This can happen if Windows is in a different boot mode, or if the Windows boot files are missing. Check /boot/efi/EFI/Microsoft for Windows files.

Can a Windows update remove GRUB?

Yes, Windows updates can overwrite the bootloader. Reinstall GRUB after such updates.

What is the difference between BIOS and UEFI boot?

BIOS uses MBR and is older. UEFI uses GPT and supports larger disks and faster boot. Both systems must match for GRUB to detect Windows.

What should I do if none of these methods work?

Consider using boot repair tools like Boot-Repair on Ubuntu, or reinstalling Windows and Linux in the same boot mode.

12. Conclusion

The linux grub not showing windows issue is common but fixable. By enabling os-prober, updating GRUB, and ensuring boot mode consistency, you can restore dual-boot functionality. If automatic detection fails, manually adding the Windows entry is a reliable workaround. With this proven guide, you can overcome the linux grub not showing windows problem and enjoy seamless dual-boot access.

For more Linux troubleshooting, explore our Linux Hub and guides on Windows 11 overwrites Linux GRUB, GRUB Error 17 Stage 1.5, and Linux read-only file system. With the right approach, you can resolve the linux grub not showing windows error quickly.