I've tried to install elementary OS alongside Windows 10 in a UEFI machine. I first did it with Secure Boot enabled, using the "something more" option. I created the boot, root and swap partitions as I always do. But the strange thing is, when the installation ended and the machine was rebooted, Grub did not showed up and Windows was loaded instead. Then I retried disabling Secure Boot, and the same thing happened, so I loaded the live CD and reinstalled and updated grub from a chrooted partition as seen here: same result. I get the same results with Ubuntu 15.10. Same thing trying the option "Install alongside Windows" instead of "Something more".
After that, I followed this tutorial with no luck. Basically, I disabled Secure Boot and Fast Startup, created all neccessary partitions and installed elementary. No repairing tools like EasyBCD or Boot Manager have been useful so far.
Can someone point me in the rigth direction? What am I missing here?
My machine is an Alienware X51 R3 with a Samsung’s PM851 M.2 SSD and Windows 10 installed. I have previously succeded double-booting Windows 10 + Elementary OS in an Alienware X51 R2 and a Samsung EVO 840 SSD.