Last year i purchased a Toshiba machine with Windows 8 preinstalled. After hard time, i managed to have dual boot on both OS. But accidentally, i updated Ubuntu and now i can not get the dual boot screen and the machine boots directly to Windows.

1) I tried the boot-repair and in the end i get "An error occurred during repair" , And i get the following report the report

It did not work

2) I tried also , on a command prompt as admin, to run the command "bcdedit /set {bootmgr} \EFI\ubuntu\grubx64.efi"

It did not work

Do you have any other suggestions?

Thank you in advance, Zampeta


Best is to reinstall GRUB in EFI mode (boot installation/repair media always using UEFI booting!)

You can also try "rEFInd" - pretty good EFI boot manager.

To install rEFInd in Windows:

a) map EFI System partition using "mountvol" command to say z:

b) copy downloaded rEFInd files to z:\refind, add boot entry for rEFInd

c) reboot selecting rEFInd as boot choice

rEFInd is like a software switch allowing you to boot to Windows, Linux and other installed OS. It seems to have its own way for discovering installed OSs not just by NVRAM entries.

  • Thanks for the answer, i am a newbie at ubuntu, how can i reinstall GRUB in EFI mode?? – user186456 Aug 17 '14 at 20:06
  • I tried:Boot from Ubuntu LiveCD or bootable pen drive. Select 'Try Ubuntu', you can manually recover your grub and fix your MBR. Open the terminal Ctrl+Alt+T and run fdisk -l to check the partition from which you want to recover GRUB 2. From your attached link of report it is clear that your Ubuntu is installed in /dev/sda7 and Swap is in /dev/sda8. Thus you have to recover it from /dev/sda7. Then run the following commands: $sudo mkdir /media/sda7 But i get an error permission denied. – user186456 Aug 18 '14 at 5:32

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