Im running windows 7, I have 1 HDMI output on my computer and two displays. I have both screen running with an HDMI splitter. Currently they're just duplicates of each other. No matter what I try I cant extend them and treat them like one single screen. How do I do this with my current set up. I've seen videos saying you can increase the resolution to 3840 by 1080 to get it to work, however mine will not let me increase the resolution in such a way.