I've tried several different things to try and fix this but can't seem to figure out why exactly this keeps happening. A little help please?

This is what I'm using, 

Is the window "Mod System Installer" supposed to be open when you do ->

• Hold down shift and right-click an empty space, then select "Open command window here".
  
  I'm struggling to figure this out, when I hit the drop down and open for the file in my browser nothing actually came up

Does it need to be in windows explorer specifically, when I tried this in my chrome browser nothing happened like I said in my last comment.

 

This is what it brought up when I opened it from the desk top, I tried from the desk top and from explorer both ways I'm not able to find the "Open command window here" bit. Is this supposed to be under properties or something?

Ok I got it to work after a few tries, 

So what I want to past in here is:
java -Djava.net.preferIPv4Stack=true -jar [forge-1.12.2-14.23.1.2583-installer.jar]

Cause that says its unable to access,

OH no brackets! Sorry I'm not a programmer so I'm not used to some of this stuff, thank you for your help and patients.
X'D