Question Duplicate screen problem

[iam4ever]

Hello everyone,
i have this annoying problem:
I am trying to duplicate screen on laptop. Right now i am using windows 7 but before that i had the same problem with windows 10. Laptop model is - dell inspiron n5110. It has 2 GPU's - one integrated and other is Nvidia Geforce GT 525M. Laptop has 2 outputs for possible connection with other monitor or TV. One of this outputs is HDMI - connected to Nvidia card, and other is VGA - connected to integrated graphics. Laptop display is also connected to integrated graphics.
If i connect monitor to VGA output i can do all that - display on 1, duplicate, extend, display on 2 with no problems.
If i connect monitor to HDMI output i can do all except duplicate.

Laptop is about to be used in kinder garden and idea is to easily used by teacher there, so i had to find a way to use HDMI output because of the audio.
Right now i am out of ideas.
Thanks all in advance.

 

[hang-the-9]

Make sure BIOS and video drivers (both for Intel and nVidia) are updated from Dell support site. Don't use drivers from nVidia site, use the ones from Dell. What exactly happens when you try to duplicate the screen, any error messages?

 

[iam4ever]

hello,
when i try to duplicate, there is a little flickering on TV and then no signal, and on main display resolution decreases to 800x600.
I try with new drivers and that from Dell site. Funny thing is that if i delete all GPU drivers and then install the one from DELL site, when i connect second screen, windows automatically duplicate screen with no problem. But if i touch anything like ... pressing even once WinKey+P i cannot duplicate again unless i uninstall and reinstall drivers again.
Right now it is in the kinder garden and so far it is working, but i am not satisfied of solution