I have plugged in two different monitors to both Dell's display dock WD15 and directly into the HDMI port on the back of the Dell laptop - Latitude 5840. I am using usb-c for the dock. The display dock will function with mouse and keyboard, but I cannot get windows or intel's display driver to recognize the additional monitor. Both the display dock and going directly into the back of the laptop with an HDMI cable has provided no result. I have used different HDMI cables and different monitors. Intel display driver on the laptop is from November of last year, I try to update it to current, and perhaps my limited admin functions do not allow me to update it OR intel's driver will not recognize and update (intel 620). Quickly getting frustrated with the inability to output my work laptop to another monitor as 14'' of display space is not going to work well with excel, etc. Please help!