How to make sure that the “main display” (out of the three available) and the labels on it do not go astray at the next OS start?

Question

Video cards

I finally installed three monitors on a computer with an i7-4771 (integrated video like Intel HD Graphics 4600). Three of the 4 available video connections are used - DVI, DisplayPort, VGA (HDMI remained unused). The monitors are not the same, and it so happened that the one connected via DVI had to be installed in the middle and assigned as the main ones - simply because it is the largest and the only one of all that has a DVI input. It contains the Taskbar and almost all the shortcuts for managing the OS, utilities and applications. But the system strongly rested and tried to make the side that is connected via DisplayPort the main one. After several returns to the position I needed, she seemed to "let herself be persuaded" and stopped kicking when she rebooted, agreeing with the given one.
And yet, not always, but quite often (about once out of 5 ... 10 inclusions), the system kicks up and arbitrarily assigns the same side, connected via DisplayPort, as the main one, and throws all the labels on it, collecting them in orderly rows near the left screen edges. You have to manually call the "Properties" of the middle screen-> Resolution-> Set as the main display, after which, again, manually distribute the labels according to the usual scheme.
Is there a way to fix the "main display" and the tabs on it in a given position once and for all, or at least automate this return at the next start of the computer?

Answer 1

There was a hassle with choosing the "correct" display from 2 (both DP or DP + DVI). It was decided by sticking into the "correct" ports.
Wants a computer as the main DP - buy him a DP-DVI cable or adapter, and you will all be happy!
Or what do you have with ports on monitors?