PC DVI to laptop VGA?

Question

Iron

Can I buy and insert a "DVI-to-VGA" adapter and then insert a VGA-to-VGA cable into the video card of the computer and from there connect it to the laptop in order to use the laptop as an additional screen to a desktop computer, Or is the VGA port on a laptop designed to connect a laptop to a monitor and not as an input?
If so, how can I make the laptop act as an additional monitor?

Answer 1

No. Only if you have a video input (and not an output where you want to connect).
Well, or purely programmatically.

Answer 2

https://www.zoneos.com/zonescreen.htm
https://avatron.com/get-air-display/
www.thg.ru/display/maxivista/maxivista-01.html