Laptop as second monitor

[alexanderroyalstills]

So, I've been looking for a few days on how to use laptop as second monitor. I know that hdmi, dvi and vga ports of the laptop are only for output and not input. I could use programs like spacedesk.ph or maxivista but I have a really slow internet so it would be unuseless. I was wondering, could I use and usb to vga/dvi/hdmi adapter for doing this? Maybe one adapter that support input? Hope this will make sense . Sorry for my bad english, thanks in advice!

 

[CountMike]

Can't you just network them and use laptop for streaming ?