I am trying to hook up a third monitor to my pc and I have everything enabled, but it still doesn't show up. I am trying to hook up a vga only monitor to an amd radeon hd 7770. The problem is, I don't have a dp monitor. I have hdmi to vga and dvi to vga. I am trying to not spend money. How can I get the third monitor hooked up using intel graphics. I am using an xps 8500.