Radeon R9 390 second display non-functional

[zMCFX2]

Sorry if I messed this up, I am new to the site and I'm not sure the point of that "ask a question" box just yet, sorry if it turns out to look like spam.

Build specs:
i5-6600K Overclocked (4x4.6GHz)
z170xp-sli mobo
16GB DDR4-2400
Radeon R9 390 8GB
GPU box says it supports 4 monitors at 4K. Both my displays are 1080.
All internals are connected properly.
Windows 10 Enterprise
And if my question got lost its also here: http://pastebin.com/6h5A0iif

List of connected USB devices:
Disk drive
USB hub (3.1 -> 4x3.0)
Keyboard
Mouse
Lastly, my speakers are connected through the functional monitor (which uses HDMI).

Since there is apparently confusion, I will repeat again, THE SECOND MONITOR IS NOT DETECTED BY WINDOWS.

 

[Darkbreeze]

Have you right clicked on the desktop, selected display settings, on the display tab scrolled down and selected advanced settings, on the advanced settings tab selected "extend these displays" instead of "display desktop only on "whichever monitor it shows"?