Drivers and all that aside, you didn't write how you enabled the second display in Windows.
I recently bought a new Samsung 1080p monitor with an HDMI and VGA port at the back. I wanted to hook it up to my Asus ROG GL702VMK (running a GTX1060) via HDMI but sadly it just displays a black screen on the monitor. The computer recognizes the monitor though and if I try to change the output resolution to 480p, it does display on the monitor. I have tried 3 different HDMI cables and it still didnt work. I've tried the cables and the monitor to a different laptop and the cable and monitor seem to be working fine. I also tried using the VGA port on the monitor and connected it to my laptop's HDMI port using a VGA-HDMI adapter and it was able to output at 1080p but not as clear and crisp as the HDMI on the other laptop.
I also tried installing the Samsung monitor drivers and I've tried updating my nvidia drivers to the latest version but still nothing.
The only problem i see is trying to connect my laptop to the monitor HDMI to HDMI at 1080p. I'm really lost