I am setting up a Dell 7400 laptop with 3 external monitors using a D6000 dock. For some reason I can't get it to detect the 3rd external monitor. It will use the laptop screen as the 3rd monitor, but the employees all have a external monitor I'm confident the graphics card. I was trying do a daisy chain setup using a DVI-DP cable and 2 DP cables. I'm not sure if I need a special driver or what.