View Full Version : [ubuntu] Fixing GRUB on Samsung NP355E5C with EFI

March 25th, 2013, 07:20 PM

I have a problem with booting Windows from GRUB menu.

I installed boot-repair and tried to fix the GRUB by "Recommended repair", but it stuck on "Reinstall GRUB. This may require several minutes.". I was waiting about two hours, then I pressed "cancel".
I tried again, but also unsuccessfully.


I would be grateful for your help.

March 25th, 2013, 07:52 PM
Does Ubuntu boot ok?

Are you running the very newest version of Boot-Repair. I saw just yesterday Yann was making fixes for just that issue.

You can manually add correct Windows boot entries. Boot-Repair scans for efi files and adds boot entries to 25_custom. But you can manually add to 40_custom. Bug report has several examples.

grub2's os-prober creates wrong style (BIOS) chain boot entry
type of entry from Boot-Repair that should work.
'Windows UEFI loader'
Type of entry that does not work:
'Windows ...) (on /dev/sdXY)'

If you use UUID (red in example below)

# To clear cache and get new view:
sudo blkid -c /dev/null -o list
Then add one or both of below examples with changes to 40_custom
gksudo gedit /etc/grub.d/40_custom

menuentry "Windows 7 UEFI" {
search --file --no-floppy --set=root /efi/Microsoft/Boot/bootmgfw.efi
chainloader (${root})/efi/Microsoft/Boot/bootmgfw.efi

menuentry "Windows bootmgfw.efi " {
search --fs-uuid --no-floppy --set=root 18FE-69D8
chainloader (${root})/EFI/Microsoft/Boot/bootmgfw.efi