The PC I was working with has 2 hard disks. One of them was using Windows 10 and the other one was used as an additional storage. I burned Ubuntu 16.04.4 using Rufus (default configuration, including the partition scheme) on a USB Drive. I shrank the second drive so that I had around 900 GBs unallocated, and when I installed Ubuntu I chose “Install along with Windows”. It automatically installed it there. As a result, I got 2 EFI partitions: the one that I had before (windows) and a new one in the second drive. Finally, to make all of this work, I had to go to the BIOS (F10) and disable Secure Boot and change the order (first ubuntu, second windows).
[Solved] Dual boot Windows 10 + Ubuntu 16.04 in HP OMEN
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