Ubuntu – Trouble with dual boot after Windows 10 update, used bcdedit, now can’t access BIOS

dual-bootgrub2windows 10xubuntu

I'm running Windows 10 and Xubuntu. I had a windows update few days ago. After that, the GRUB menu disappeared. The solution I used was loading Windows and from command prompt using

bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi 

as suggested in Windows 10 upgrade kills grub and boot-repair doesn't help.

This partially solved the problem, now I get to the GRUB and I can load both Windows and Xubuntu BUT after lots of errors before I get to GRUB.

First, when the laptop turns on, I have a few statements:

Failed to open \EFI\Boot\grubx64.efi - Not Found
Failed to load image \EFI\Boot\grubx64.efi: Not Found
start_image() returned Not Found
Failed to open \EFI\BOOT\grubx64.efi - Not Found
Failed to load image \EFI\BOOT\grubx64.efi : Not Found
start_image() returned Not Found 

Then it goes to next screen and it shows me this message:

Default Boot Device Missing or Boot Failed.
Insert Recovery Media and Hit any key
Then Select 'Boot Manager' to choose a new Boot Device or to Boot Recovery  

After I click "Ok" (which is the only option here to click), it loads Boot Manager screen:

Boot Option Menu

1. Linpus lite(TOSHIBA MQ01ABF050)

After I click enter because I only have one option here, it repeats error messages I already had on start:

Failed to open \EFI\Boot\grubx64.efi - Not Found
Failed to load image \EFI\Boot\grubx64.efi: Not Found
start_image() returned Not Found
Failed to open \EFI\BOOT\grubx64.efi - Not Found
Failed to load image \EFI\BOOT\grubx64.efi : Not Found
start_image() returned Not Found 

After this, it just loads GNU GRUB with options to choose from Windows and Ubuntu(Xubuntu) etc.

From this point, everything works as usual. I do not get any errors or experience any kind of problems while working on Windows or Xubuntu.

My boot order is set to USB first and Hard Drive second.
I tried to change order after I experienced this problem but now I cannot even access my BIOS. This is very unusual behavior, I always could access my BIOS. Now when I press F2 on startup, it doesn't load into BIOS, it asks me for a password. I never set a password for BIOS and I am the first owner of this laptop, nobody else ever used it either. So no mistake there.

I tried just clicking enter and leaving password field blank as I read somewhere but it didn't work.

As I'm a complete newbie to these kind of things, I tried to repair GRUB from Xubuntu but this didn't improve situation (or made it worse).

I'm looking for a solution that includes repairing bcdedit thingy.

Reseting laptop is not a solution right now, I am leaving that as my last option because I have a lot of files to transfer and a lot of projects currently in progress.

Thank you all in advance.
And yes, I realize I shouldn't have messed with bcdedit if I'm clueless about it.


As oldfred suggested, I copied all files from /EFI/ubuntu to /EFI/BOOT folder and problem with errors was solved. Or I don't see it anymore, can't tell.

Problem with system asking for BIOS password is still there. I repeat: I never set password; It worked before whole grub mess just fine (I was able to access BIOS); Password isn't blank.

Best Answer

  • I had the same problem - dual boot Windows 10/Lubuntu computer which would no longer show the GRUB dual boot menu after the Spring 2018 Windows 10 upgrade.

    On my Dell machine the F12 key brings up a Boot Order menu. On other devices, this kind of menu or the BIOS/UEFI firmware may be accessed by another F key or by esc or del. This saved me a lot of potential work: I kept pressing F12 during startup, and the computer went into its own boot menu with separate entries for Windows and Lubuntu.

    I selected Lubuntu, and then I opened a Terminal and entered

    sudo grub-install /dev/sda

    (both operating systems are on /dev/sda on my computer). GRUB dual boot menu was reinstalled and dual boot is working fine again. Total time about 3 minutes. Hope your system has the same options available.