I have a macos and Windows 10 already installed. I went ahead and installed ubuntu via EFI, and I think I really messed something up.

Every time I boot and select Windows it goes to the purple Ubuntu boot manager. I really need access to Windows, as it has my work files on there. Is there a way I can go back to having boot camp launch windows instead of Ubuntu?

I can access Ubuntu, however.

  • What is the model/year of your Mac? Sep 3, 2018 at 13:13
  • Hi there, it's a Mac Mini, late 2014. Core i5 with 8GB of ram . macos 10.13.6 Sep 3, 2018 at 20:24

2 Answers 2


Why are you even using Bootcamp it’s not necessary.. just install a boot loader and pick whatever you need at the start. If you want to run particular windows apps just use Wine Wine Is Not an Emulator

  • Hi Jack. There is some enterprise level software that won' t work on Wine, unfortunately. Thanks Sep 4, 2018 at 2:11
  • @AmanBasanti in that case I think you should just nuke the other systems you have previously installed and install windows as dual boot WITHOUT using bootcamp. Bootcamp is for novice users, you can do it without bootcamp in a much better way, just google for a tutorial there are many great ones. Sep 5, 2018 at 1:21
  • 1
    That's what I ended up doing. It was easy enough to retrieve the files I needed. Sep 11, 2018 at 15:00

The current releases of both Windows and Ubuntu by default install a file named BOOTX64.EFI in the EFI/BOOT folder stored in the EFI partition of your internal drive. When you installed Ubuntu, the Windows version of this BOOTX64.EFI file was overwritten with the Ubuntu version.

There is a backup copy of the windows version of the BOOTX64.EFI file which is named bootmgfw.efi in the folder EFI/microsoft/boot stored in the EFI partition.

There is a backup copy of the Ubuntu version of the BOOTX64.EFI file which is named shimx64.efi in the folder EFI/ubuntu stored in the EFI partition.

To get the EFI partition to appear in the Finder application, you will need to enter the following command in a Terminal application window.

sudo diskutil mount disk0s1
  • Okay. Let me try restoring the BOOTX64.EFI file with the Windows backup. Sep 4, 2018 at 1:02
  • Hi David, thanks for your help. I restored the BOOTX64.EFI file from the bootmgfw.efi file. Now when I select windows from the boot camp loader screen, I just get it hanging during the Windows boot. I assume that the file names are all case sensitive. My guess is since Ubuntu also resized the Windows partition, Windows may be getting annoyed with that during some type of verification during the boot process. Sep 4, 2018 at 1:39
  • @Aman Basanti: Well, if you need to rebuild the boot files, the procedure is outlined in this answer. Sep 4, 2018 at 2:40
  • Hi David. I am using those instructions and they seem straightforward however when I get to step 6 "Enter the command below to assign drive letter S to the EFI partition." - it doesn't work. Bootcamp is Vol 0, Drive D, ESD-USB (flash installer) is Vol1 letter C. Sep 4, 2018 at 4:47
  • The problem is my USB flash installer (the EFI) is already at letter C. Sep 4, 2018 at 5:07

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