Windows 10: When i plug in my 2nd monitor my main one turns off

When i plug in my 2nd monitor my main one just goes black and the 2nd one says that the input is not supported 2nd monitor is 720p and im thinking that thats why it says that. an because it doesnt show anything i cant change any setting

:)

 

2nd laptop monitor turning off when the laptop turns off

So,

I have my laptop with a 2nd monitor, is there a way to set my 2nd monitor to turn off or on when the laptop turns off or on,

basically, when I start turning on my laptop, my other 2nd monitor stays off, is there a way to make it turn on when I start my laptop, same with the shutdown?

Same with my xbox, when I turn my xbox on the monitor stays off.

Dell P2717H

Is my monitor

*Using hdmi*

 

2nd monitor

I am trying to set up a second monitor. I used the HDMI for the first monitor, no problem, but didn't have another HDMI so used the regular hookup with a adapter cord from 16 bit to hdmi. But when I plug that one in, it won't let anything open on the
first monitor and nothing on the 2nd

 

2nd monitor not working

So i recently bought my 2nd monitor and i tried to plug thr hfmi in my pc but it was just black screen then i switched my 1st monitor hdmi to the place where my 2nd monitor hdmi was and it was again just black screen. is my hdmi ports brocken or do i have to update drivers or something else pls help