HP Elitebook 8540P laptop running Win7Pro. It will only display on it's own monitor. It will not display to external monitor via the VGA or via the Display Port.
I reformatted this machine recently, put in an SSD drive and installed the OS Win7Pro. I checked Device Manager and all the drivers appear to be installed, nothing is yellow triangle. What should I look at to make this display to multiple monitors? It used to display to a total of 3 monitors: it's own screen and a screen hooked to VGA port and a 3rd screen hooked to the Display Port. Now, after reinstalling OS, when I go to Display control panel and adjust resolution, it only see's one monitor...it's own monitor, does not see the other monitors