With a fresh Windows 10 machine (Lenovo H50-55) I did a dual-boot install with Fedora 23.  The installation seemed to go fine, but when I rebooted it went straight to Windows as if there was no GRUB.  When I used Boot-Repair it found both Windows and Fedora on the machine, and its repair option chugged away, but it didn't fix the problem after a reboot; in fact, in comparing the Boot Info files from before and after the repair attempt it seems there wasn't really any changes.EDIT: I also encountered the same problem after upgrading my machine's BIOS.
Dual boot installation has no effect (no GRUB), Boot-Repair doesn't help
fedora;grub2;dual boot;uefi
I followed these instructions from It's F.O.S.S. to use bcdedit in an admin-priveledged command prompt, but with a slightly different path since it was Fedora instead of Ubuntu:bcdedit /set {bootmgr} path \EFI\fedora\grubx64.efiWhen I next rebooted I got to GRUB, which allowed me to boot into either Fedora or Windows.EDIT: The same solution also worked after GRUB was ignored after upgrading my machine's BIOS.