Using Windows 10 on my laptop and an Asus portable second monitor with USB, I can only see the screen background and tray icons on my second monitor, not the full image that appears on the laptop.
I have tried selecting the "Duplicate display", "Extended display" options but the closest I get to wanting my laptop image to be replicated on the second monitor is as described above. This problem mysteriously suddenly appeared after working perfectly for 1 year !
Have also tried updating my drivers from the video card manufacturer's website (Intel).
Can anyone help please ?