Boot-Repair created too many grub menu entries for Windows

Every time I've run boot-repair it adds a 5 extra Windows boot options to my main grub menu that do not work. In your case it has added 11 extra entries!

grub.cfg shows the problem

The secret can be found within /etc/grub/grub.cfg file:

### BEGIN /etc/grub.d/25_custom ###
    menuentry "Windows UEFI bootmgfw.efi" {
search --fs-uuid --no-floppy --set=root D656-F2A8
chainloader (${root})/EFI/Microsoft/Boot/bootmgfw.efi
}

menuentry "Windows Boot UEFI loader" {
search --fs-uuid --no-floppy --set=root D656-F2A8
chainloader (${root})/EFI/Boot/bkpbootx64.efi
}

menuentry "EFI/ubuntu/fwupx64.efi" {
search --fs-uuid --no-floppy --set=root D656-F2A8
chainloader (${root})/EFI/ubuntu/fwupx64.efi
}

menuentry "Windows UEFI bootmgfw.efi sda1" {
search --fs-uuid --no-floppy --set=root 9478-B6E2
chainloader (${root})/EFI/Microsoft/Boot/bootmgfw.efi
}

menuentry "Windows Boot UEFI loader sda1" {
search --fs-uuid --no-floppy --set=root 9478-B6E2
chainloader (${root})/EFI/Boot/bkpbootx64.efi
### END /etc/grub.d/25_custom ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows Boot Manager (on /dev/nvme0n1p2)' --class windows --class os $menuentry_id_option 'osprober-efi-D656-F2A8' {
    savedefault
    insmod part_gpt
    insmod fat
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root  D656-F2A8
    else
      search --no-floppy --fs-uuid --set=root D656-F2A8
    fi
    chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}
menuentry 'Windows Boot Manager (on /dev/sda1)' --class windows --class os $menuentry_id_option 'osprober-efi-9478-B6E2' {
    savedefault
    insmod part_gpt
    insmod fat
    set root='hd0,gpt1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1  9478-B6E2
    else
      search --no-floppy --fs-uuid --set=root 9478-B6E2
    fi
    chainloader /efi/Microsoft/Boot/bootmgfw.efi
}
### END /etc/grub.d/30_os-prober ###

The section 30_os-prober contains the "good" Windows grub menu entries you want to keep. Section 25_custom contains the bogus entries created by boot-repair. You can't edit the grub configuration file because it will simply be overwritten the next time update-grub is run.

Section 25_custom was created by Boot Repair

On my system:

$ locate 25_custom
/boot/efi/boot-repair/log/20171111_224241/nvme0n1p5/25_custom
/boot/efi/boot-repair/log/20171208_030854/nvme0n1p5/25_custom
/etc/grub.d/25_custom

Take a look at the extra Windows options that were setup (and don't work):

$ cat /boot/efi/boot-repair/log/20171208_030854/nvme0n1p5/25_custom
#!/bin/sh
exec tail -n +3 $0

menuentry "Windows UEFI bootmgfw.efi" {
search --fs-uuid --no-floppy --set=root D656-F2A8
chainloader (${root})/EFI/Microsoft/Boot/bootmgfw.efi
}

menuentry "Windows Boot UEFI loader" {
search --fs-uuid --no-floppy --set=root D656-F2A8
chainloader (${root})/EFI/Boot/bkpbootx64.efi
}

menuentry "EFI/ubuntu/fwupx64.efi" {
search --fs-uuid --no-floppy --set=root D656-F2A8
chainloader (${root})/EFI/ubuntu/fwupx64.efi
}

menuentry "Windows UEFI bootmgfw.efi sda1" {
search --fs-uuid --no-floppy --set=root 9478-B6E2
chainloader (${root})/EFI/Microsoft/Boot/bootmgfw.efi
}

menuentry "Windows Boot UEFI loader sda1" {
search --fs-uuid --no-floppy --set=root 9478-B6E2
chainloader (${root})/EFI/Boot/bkpbootx64.efi

These are the erroneous entries boot-repair created in /etc/grub.d/25_custom that were subsequently compiled into \boot\grub\grub.cfg.

Reverse Boot Repair's change to 25_custom

Use sudo -H gedit /etc/grub.d/25_custom and delete everything except the first three lines:

#!/bin/sh
exec tail -n +3 $0
  • The file now contains two lines with text and one blank line.
  • Save the file.
  • Run sudo update-grub.
  • Reboot.

Now your menu is no longer bloated with five bogus Windows menu entries that don't work.

Double-check there are three lines in 25_custom

Run this command and verify 25_custom has three lines:

$ wc /etc/grub.d/25_custom
      3       6      30
#     ^       ^       ^
#     |       |       +--- Number of characters
#     |       +----------- Number of words
#     +------------------- Number of lines

I added the # comments to decipher wc (word count) output.


Windows is off-topic here, but the answer is that this is very old technology and the boot sector is only 512 bytes, so it's not big enough to hold everything we would like it to hold.

To easily add and remove entries from grub all on your own, please:

  1. Take a full system back-up of your entire computer including the other OSes using CloneZilla Live
  2. No, I wasn't kidding! Take a full system back-up first! :-)
  3. Whenever someone tells you to install a PPA be very cautious, do your own research if this is what you really want and only then continue

  4. Install grub-customizer by executing the following commands:

    sudo add-apt-repository ppa:danielrichter2007/grub-customizer
sudo apt update
sudo apt install grub-customizer

  5. Start grub-customizer and customize the hell out of it: enter image description here

  6. If you run into serious trouble, restore your system back-up.

Tags:

Uefi

Grub2

Dual Boot

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