No windows in grub menu

asked Oct 8, 2012 at 16:20

1. Boot Ubuntu and mount your Windows partition (simply open the disk on Nautilus)

2. Run the following on the command line (Ctrl+Alt+t):

   sudo os-prober
   

3. If your Windows installation was found, you can run:

   sudo update-grub
   

Note that step 2 is just for your convenience. You could just mount the Windows 7 partition and then run update-grub.

Related question

• Unable to mount Windows (NTFS) filesystem due to hibernation

If the os-prober method above doesn’t work try adding a custom grub menu entry. Documented here.

First two steps are for finding your <UUID>.

1. Run lsblk and find the name of the row with /boot/efi

Example output (here the answer is sda2):

lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda           8:0    0   477G  0 disk 
├─sda1        8:1    0   450M  0 part 
├─sda2        8:2    0   100M  0 part /boot/efi
├─sda3        8:3    0    16M  0 part 
├─sda4        8:4    0    47G  0 part /windows
├─sda5        8:5    0 425,6G  0 part /
└─sda6        8:6    0   3,7G  0 part [SWAP]
mmcblk0     179:0    0  14,9G  0 disk 
└─mmcblk0p1 179:1    0  14,9G  0 part

1. Run sudo blkid /dev/sdaX where sdaX is the answer from previous step (sda2 in my case).

Example output (here the answer is 58E4-427D):

/dev/sda2: UUID="58E4-427D" TYPE="vfat" PARTLABEL="EFI system partition" PARTUUID="b81727be-ba90-5f8c-ab98-d3ec67778b7d"

1. Add the following at the end of the file /etc/grub.d/40_custom:

menuentry "Windows 7" {  
     insmod ntfs  
     set root='(hd0,1)'  
     search --no-floppy --fs-uuid --set <UUID>
     chainloader +1  
}

1. Run sudo update-grub and reboot.

I had Windows 10 running and then tried dual boot. Once Ubuntu was installed, Win 10 wasn’t showing up in my GRUB loader. I tried the following —

First of all, I disabled Secure Boot in Win10. Then ran the below
commands in Ubuntu :

sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair

Worked out pretty well. Was able to find both Windows and Ubuntu in GRUB after that.

RutrusRutrus

1,5011 gold badge9 silver badges10 bronze badges

Slightly different method as I copied from a working example on another computer, posting for my own records.

Append the following to /etc/grub.d/40_custom:

menuentry "Windows 10" {
        insmod part_gpt
        insmod fat
        search --no-floppy --fs-uuid --set <boot_efi_uuid>
        chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}

where <boot_efi_uuid> is the UUID of your /boot/efi partition. To find this:

$ lsblk
NAME              MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT                                                  
sda                 8:0    0 119.2G  0 disk
└─md126             9:126  0 357.7G  0 raid0
  ├─md126p1       259:0    0   499M  0 md
  ├─md126p2       259:1    0   100M  0 md    /boot/efi                                                   

$ sudo blkid | grep md126p2 # Replace with your device
/dev/md126p2: UUID=<boot_efi_uuid>

Then of course, once you’re saved the file, run:

sudo update-grub

Reboot, you should now be able to successfully start up Windows.

answered Feb 16, 2019 at 23:45

If you have previously had a RAID installed that may be causing issues. In my case, I built my desktop in 2010, and I installed two 1.5 TB with a striped RAID. User gracemercy54 mentions here that this is left over metadata from the former RAID configuration.

When I originally tried the steps by Hermes I got an error specifying «wrong number of devices in a RAID set.» So, if this happens to you open a terminal and run:

   sudo dmraid -rE
   sudo os-prober
   sudo update-grub

That fixed this for me.

answered Mar 18, 2017 at 18:56

answered Dec 4, 2017 at 22:50

I had the same problem with Windows 10. I installed Linux Mint 18.1 Cinnamon 64-bit on my laptop for dual boot with WIN10. After the installation GRUB only offered to boot Linux but not Windows.

I found the video solution for windows 10 missing from grub menu and the forum thread Grub not recognizing Win10 after Update/Repair, but unfortunately neither worked for me so I used a combination of these two to resolve my problem.

Open your terminal and follow these commands and open the file named 40_custom:

sudo gedit /etc/grub.d/40_custom

Add these lines to the end of the file and then save and exit:

menuentry "Windows 10" {
   set root='{hd0,1}'
   chainloader + 1
}

After you save the file update your GRUB with this command:

sudo update-grub

Then restart your machine to see if it works.

Hope this will work for others too!

Edit: As @Guss specified, this should be configured in /etc/default/grub, not the built-in script.

Old answer:

Follow these steps if os-prober shows Windows, but GRUB does not.

• Edit grub-mkconfig

  sudo nano /usr/bin/grub-mkconfig
  

• Find these lines near the middle

  # Disable os-prober by default due to security reasons.
  GRUB_DISABLE_OS_PROBER="true"
  

• Change true to false
• Exit nano (CTRL+X, Y, Enter)
• Update GRUB

  sudo update-grub
  

answered Mar 11, 2021 at 13:16

I had the same issue after I installed the updates from ubuntu. The following commands worked for me perfectly:

sudo apt-get install os-prober

First install os-prober to detect windows and then update grub:

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

answered Oct 29, 2019 at 21:02

asked Oct 8, 2012 at 16:20

1. Boot Ubuntu and mount your Windows partition (simply open the disk on Nautilus)

2. Run the following on the command line (Ctrl+Alt+t):

   sudo os-prober
   

3. If your Windows installation was found, you can run:

   sudo update-grub
   

Note that step 2 is just for your convenience. You could just mount the Windows 7 partition and then run update-grub.

Related question

• Unable to mount Windows (NTFS) filesystem due to hibernation

If the os-prober method above doesn’t work try adding a custom grub menu entry. Documented here.

First two steps are for finding your <UUID>.

1. Run lsblk and find the name of the row with /boot/efi

Example output (here the answer is sda2):

lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda           8:0    0   477G  0 disk 
├─sda1        8:1    0   450M  0 part 
├─sda2        8:2    0   100M  0 part /boot/efi
├─sda3        8:3    0    16M  0 part 
├─sda4        8:4    0    47G  0 part /windows
├─sda5        8:5    0 425,6G  0 part /
└─sda6        8:6    0   3,7G  0 part [SWAP]
mmcblk0     179:0    0  14,9G  0 disk 
└─mmcblk0p1 179:1    0  14,9G  0 part

1. Run sudo blkid /dev/sdaX where sdaX is the answer from previous step (sda2 in my case).

Example output (here the answer is 58E4-427D):

/dev/sda2: UUID="58E4-427D" TYPE="vfat" PARTLABEL="EFI system partition" PARTUUID="b81727be-ba90-5f8c-ab98-d3ec67778b7d"

1. Add the following at the end of the file /etc/grub.d/40_custom:

menuentry "Windows 7" {  
     insmod ntfs  
     set root='(hd0,1)'  
     search --no-floppy --fs-uuid --set <UUID>
     chainloader +1  
}

1. Run sudo update-grub and reboot.

I had Windows 10 running and then tried dual boot. Once Ubuntu was installed, Win 10 wasn’t showing up in my GRUB loader. I tried the following —

First of all, I disabled Secure Boot in Win10. Then ran the below
commands in Ubuntu :

sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair

Worked out pretty well. Was able to find both Windows and Ubuntu in GRUB after that.

RutrusRutrus

1,5011 gold badge9 silver badges10 bronze badges

Slightly different method as I copied from a working example on another computer, posting for my own records.

Append the following to /etc/grub.d/40_custom:

menuentry "Windows 10" {
        insmod part_gpt
        insmod fat
        search --no-floppy --fs-uuid --set <boot_efi_uuid>
        chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}

where <boot_efi_uuid> is the UUID of your /boot/efi partition. To find this:

$ lsblk
NAME              MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT                                                  
sda                 8:0    0 119.2G  0 disk
└─md126             9:126  0 357.7G  0 raid0
  ├─md126p1       259:0    0   499M  0 md
  ├─md126p2       259:1    0   100M  0 md    /boot/efi                                                   

$ sudo blkid | grep md126p2 # Replace with your device
/dev/md126p2: UUID=<boot_efi_uuid>

Then of course, once you’re saved the file, run:

sudo update-grub

Reboot, you should now be able to successfully start up Windows.

answered Feb 16, 2019 at 23:45

If you have previously had a RAID installed that may be causing issues. In my case, I built my desktop in 2010, and I installed two 1.5 TB with a striped RAID. User gracemercy54 mentions here that this is left over metadata from the former RAID configuration.

When I originally tried the steps by Hermes I got an error specifying «wrong number of devices in a RAID set.» So, if this happens to you open a terminal and run:

   sudo dmraid -rE
   sudo os-prober
   sudo update-grub

That fixed this for me.

answered Mar 18, 2017 at 18:56

answered Dec 4, 2017 at 22:50

I had the same problem with Windows 10. I installed Linux Mint 18.1 Cinnamon 64-bit on my laptop for dual boot with WIN10. After the installation GRUB only offered to boot Linux but not Windows.

I found the video solution for windows 10 missing from grub menu and the forum thread Grub not recognizing Win10 after Update/Repair, but unfortunately neither worked for me so I used a combination of these two to resolve my problem.

Open your terminal and follow these commands and open the file named 40_custom:

sudo gedit /etc/grub.d/40_custom

Add these lines to the end of the file and then save and exit:

menuentry "Windows 10" {
   set root='{hd0,1}'
   chainloader + 1
}

After you save the file update your GRUB with this command:

sudo update-grub

Then restart your machine to see if it works.

Hope this will work for others too!

Edit: As @Guss specified, this should be configured in /etc/default/grub, not the built-in script.

Old answer:

Follow these steps if os-prober shows Windows, but GRUB does not.

• Edit grub-mkconfig

  sudo nano /usr/bin/grub-mkconfig
  

• Find these lines near the middle

  # Disable os-prober by default due to security reasons.
  GRUB_DISABLE_OS_PROBER="true"
  

• Change true to false
• Exit nano (CTRL+X, Y, Enter)
• Update GRUB

  sudo update-grub
  

answered Mar 11, 2021 at 13:16

I had the same issue after I installed the updates from ubuntu. The following commands worked for me perfectly:

sudo apt-get install os-prober

First install os-prober to detect windows and then update grub:

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

answered Oct 29, 2019 at 21:02