Using correct display driver and you can only use external display?

Dell laptops do not use Intel drivers downloaded from Intel. Those drivers are customized by Dell for each model's motherboard and must be downloaded from Dell. Reinstall the original Dell drivers for the hardware you have which are rarely if ever updated by Dell. https://www.dell.com/support/home/us/en/19/product-support/product/latitude-e5570-laptop/drivers

@Mary G  somebody saying they're using an Intel display driver does not necessarily mean it came from Intel.  The display drivers on support.dell.com are still called Intel display drivers.

@TM1984  assuming you are in fact using an Intel display driver that came from Dell, when it's installed, what do you see in Windows Display Settings and/or Intel HD Graphics Control panel.  It's possible that at some point the system was configured to disable the built-in display when an external display was attached and the drivers are simply remembering that preference, since some people specifically don't want their built-in display active when they have external displays.  In that case, you should be able to just go to Windows Display Settings, select the built-in display, and choose mirror/extend on that display.  It might just have been set to "Do not use this display" previously.

Hi @MaryG and @jphughan We've downloaded newest drivers using Dell Command Update and also directly from Dell.com support site using service tag. With Intel driver: The Windows display settings shows only one display depending if you have external display attached or not, but in the boot both displays work just fine. If I install the Intel driver, only one display works and you are able to see the share display option to another display, but it doesn't clone, extend etc. And if I have external display attached while booting to windows, the windows cannot see laptop's own panel, only the external one and vice versa. With Microsoft's display driver: The laptop's own display works but Windows cannot see the external display. With Microsoft driver you cannot use display cloning, extending etc. on Win10. And ofcourse on the boot both displays work. We have also reinstalled Win10 to this particular laptop and that didn't help either - I'm running out of options.

That’s very strange. I wonder if this is a driver bug that might affect a handful of system models. Try going to support.dell.com, searching for your system model, going to the Drivers area, searching “Intel Graphics”, clicking the More Details link for the driver package, and then selecting “View older versions”. See if maybe a previous release works properly. If it does, you might have to disable this particular update on Dell Command | Update at least until a new release that doesn’t have this problem becomes available. And if you haven’t just performed a clean install, you’ll need to uninstall the newer version before installing an older one.

@jphughan thanks! Actually I haven't tried out older driver yet - I'll try that next. 

Hi! I have the same problem as you... Did you solve it? Thnx!