Back story:
I have two identical monitors attached to my machine (both Dell U2412M). The one that I was using as the primary display flaked out a couple of times over the last week (went momentarily blank) and came back (I actually had a similar problem a few months ago with another monitor
) . So, I thought I'd swap the two monitors over to see if it was a problem with that port on the graphics card, or the monitor itself.The original setup was that the primary monitor was designated as #1 and it was right in front of me. The secondary monitor was #2 and sat off to the right.
When I swapped the monitors over, that's literally all I did. I unplugged the cables, left the cables sitting exactly where they were, physically swapped the monitors and then plugged them in. So, the monitor in front of me was the one that had previously been the #2 secondary monitor and vice versa but the cables were in the same position. i.e. the monitor now in front of me may be physically a different one but it is plugged into the port that the primary monitor was always plugged in to and the one off to the right is plugged in to the slot that the secondary one was always plugged in to.
But here is the weirdness. Everything that I have read tells me that which monitor gets what number allocated to it depends on the port they are plugged in to. So, the monitor in front of me, even though it is a different physical unit (of exactly the same model) should still be #1 right? Because it is plugged in to the port that monitor #1 always was, right? But it isn't. It's got number #2 and the one off to the right has #1 as its allocation.
Yup, it was the whole shooting match. When I switched on, the displays were reversed (stuff that should have been on the right screen was on the left, I had to move mouse left to get it on to the right screen etc) and the monitor in front of me was being treated as the secondary monitor.
Easy to fix right? Just go into display settings and drag the monitors to their correct positions relative to each other, tell Windows to make monitor #2 the primary display and we're good right? It doesn't actually matter which monitor is called 1 and which is called 2 in the background as long as Windows knows which is the primary and which is the secondary, right? So I did that. I also checked that there was nothing additional that I could do in the nVidia display options (couldn't see anything).
Most of the time, that solves the situation and it doesn't matter which one is called 1 or 2, it's which one is main and which one is secondary that's important. However, certain programs (mostly older games and, unfortunately, GZDoom) seems to default to display #1 regardless of which display is set to be primary. I know that in the case of GZDoom, there is a variable that I can set to tell it to use display #2 (I've done that) but some other programs don't have that option.
So, does anyone know of a way to force Windows to call a particular monitor #1 and #2? As I said, everything I have read says no and that the numbers are determined by which port the monitors are actually plugged in to. However, that doesn't seem to be the case, because I did not change the ports that the monitors are plugged in to relative to their positions on the desk (and the monitors are identical models anyway) but the numbers went with the monitors, not the ports, apparently.