I can successfully install Windows 8.1 on a Samsung Series 5 Ultra, but when I try to boot the system it only shows a menu with the main HDD as an option. I select it and nothing happens. The only way to boot into Windows is through the installation USB by selecting "Repair..." and then "Continue to Windows 8.1" (I'm translating from Spanish, I don't know how it's written in English).
Also, while the Windows installation detects there is a Windows already installed on the system, "BootRec.exe /ScanOS" doesn't.
Any ideas on what could be happening? I would appreciate any input.
Extra info: the notebook has one HDD and one SSD. The SSD es completely inaccessible during boot, for some reason.