I bought a new machine, New Intel i7 Haswell-E 6 Cores processor, 16Gb 3000MHz DDR4 Memory on a GA-X99 Mobo.

I put in it 3 new SDD Disks: One for a clean Windows 10 (Works Fine), One for a clean Hackintosh (Works fine, but have same problems with the bootloader) and one for Ubuntu Gnome x64 15.04.

In my previous machine (an old DDR2 800Mhz, Intel Core2Quad q9550 machine) Grub2 solved all my boot problems, but all the systems runs under MBR scheme and the Operating Systems shared disks.

Now all the systems boots under UEFI scheme and Grub2 do not see the other systems.

I installed Grub2 on the Ubuntu Disk with the two other OS partitions mounted on linux but grub2 can't recognize the other 2 OSs.

1 Answer 1


There is one EFI partition where you have to install all bootloaders, install GRUB to this partition.

In your case I assume, it is on sda (if you first installed Windows and installed it on the first disk).

Boot from Ubuntu GNOME install media created before.

Open a terminal and execute the following commands:

sudo mount /dev/sd*** /mnt  
sudo mount /dev/sd** /mnt/boot/efi  
for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; done  
sudo chroot /mnt  
grub-install /dev/sd*

Note : * = disk | ** = efi partition | *** = system partition

Reboot the PC and now you should be able to select all operating systems from GRUB boot menu.

  • I sadly discovered my Windows 10 Pro was installed in MBR mode (cos was an update from Windows 7, my original Licence). And it's de cause for what Grub don't see Windows partitions. I try to reinstall it en UEFI mode in the Weekend. And after that re install grub and update the results. Thanks a lot for your help!
    – fbz67
    Sep 25, 2015 at 15:02

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .