Windows and multiple displays

Donald

Donald

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Mar 21, 2004
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Have a desktop with 2 monitors.

We had the main one set to 3 and the other one set to 1&2.

I think someone might have messed with the HDMI cables going to the desktop

It's not like it was and I need to figure out how to get it back to the way it was.

I see in Windows how to do various things with monitors such as extend or duplicate but do not see how to assign a number to a particular monitor
 
Having one monitor set to 1 & 2 implies you had two cables plugged into the same screen? Normally two monitors would be two numbers, 1 & 2.

You are able to click on each of the screens in display settings and make the one you want be the primary display through the drop down below that section.
 
The numbers Windows assigns to display panels is arbitrary. Don't focus on what number has been assigned to what, only focus on if the panels are arranged how you want them. Windows just uses the numbers to keep track of how they are arranged physically compared to how it thinks they are arranged which can be manipulated by you to match.

That said, if you have two physical panels and Windows shows three, you have one of them plugged in with two cables which isn't necessarily 'bad', just wrong.
 
As others have said, it's not typical to run two outputs from the PC to one monitor - but, it may be an option (and desirable) for some people. Is this monitor which was set up as #1&#2 an ultrawide format monitor? If so, I can imagine a use case where someone wanted each side of the ultrawide monitor to act as an individual monitor - in other words, rather than having three physically separate monitors (#1, #2, #3) the ultrawide behaves as though #1 and #2 are conjoined.

Is that how you were set up before? Or were you able to have one application (a web browser, for instance) take up all of the #1/#2 monitor?
 
If you only have 2 monitors and 3 different numbers in the display settings you must have an extra cable connected to the same monitor. I'd get rid of the extra cable and then use the Identify button to determine which monitor is 1 and 2. Then set the monitor you want to be the main monitor. Windows doesn't allow you to assign the numbers to the monitors, it assigns them based on the port they are plugged into on the PC/video card.

Unless this is some special setup that requires 2 cables like a very large monitor displaying multiple different video signals on the same screen. Might also have special software installed that is handling this and the windows display settings are just the base for the video config.
 
This is a typical setup for streaming with an ATEM attached to a PC. You have PowerPoint running on the main monitor and on the secondary monitor you have the monitor split into 4 sections. One for what is going out to the stream, one for speed of the stream feed and one for local wall mounted monitors and one other.

It' almost works properly now but if you click settings, the settings window shows up on the secondary monitor and the local wall mounted monitors. Want it only on the main monitor.
 
Try opening settings, moving it to the main monitor, then closing it. Upon reopening, it should open on main.
 
right click on the desktop, go to display settings and look for multiple displays so you can move them around to suit yourself.
 
Donald said:
You mean pick up the little display icon and move it like you might move a file? I actually think I tried that. But will try it again.
Click to expand...
Yes. Drag the tiles that represent the monitors, hit apply or whatever the button was, if you get it to what you need it to be - hit whatever button allows you to confirm, and you're good.
 
So this seems to still an issue. But the related problem is each time things are powered up which display is display 1 vs 2 vs 3 and whether it's duplicate or extend.

Is there a way to save the settings or is it the way things are powered up?
 
Monitors are assigned via HWID. To change the numbers assigned, you need to go into regedit. I don't remember what keys need to be edited but I did find the registry keys via Google when I had to do it.
 
Donald said:
So this seems to still an issue. But the related problem is each time things are powered up which display is display 1 vs 2 vs 3 and whether it's duplicate or extend.

Is there a way to save the settings or is it the way things are powered up?
Click to expand...
The settings will save when you rearrange the monitors in the menu and hit Apply.

If they keep reverting to a different layout - I'd look for electrical grounding issues and static electricity discharges. Especially if your monitors are older NEC monitors.

A static discharge will joyfully turn monitors off, letting Windows rearrange what's left.
 
So I believe there are 3 physical monitor connections.

Is does it matter if all the monitors are powered up before the PC. Or power up the PC then the monitors?
 
It doesn't matter. Leave the monitors always on. Any monitor newer than 20 years should go-to sleep when the pc is off.

What could matter is if some of the monitors are on the motherboard's integrated video ports, and the others are on a separate video card. One could be getting "awake" before the other.
If you have a separate video card, chances are it comes with more than three ports. Put them all there.
If yoy have to use both motherboard and separate card - plug the monitor you consider the main desktop monitor in the motherboard's integrated video ports.
 
goblin said:
It doesn't matter. Leave the monitors always on. Any monitor newer than 20 years should go-to sleep when the pc is off.

What could matter is if some of the monitors are on the motherboard's integrated video ports, and the others are on a separate video card. One could be getting "awake" before the other.
If you have a separate video card, chances are it comes with more than three ports. Put them all there.
If yoy have to use both motherboard and separate card - plug the monitor you consider the main desktop monitor in the motherboard's integrated video ports.
Click to expand...
It's a desktop and I believe they use the main HDMI output jack and two USB to HDMI adapters plugged into USB jacks.
 
I suspect this where it breaks. That usb might be going offline, and/or not detected fast enough on restart, so for a very short tune Windows thinks it has only one monitor and acts accordingly.

Set the main monitor to be plugged in the bona fide hdmi. Check the power settings and make sure you disable any and all USB power optimizations (put USB to sleep, etc - disable these if any). But at the end of the day, installing a cheap dedicated video card might be the way to go.
 
goblin said:
I suspect this where it breaks. That usb might be going offline, and/or not detected fast enough on restart, so for a very short tune Windows thinks it has only one monitor and acts accordingly.

Set the main monitor to be plugged in the bona fide hdmi. Check the power settings and make sure you disable any and all USB power optimizations (put USB to sleep, etc - disable these if any). But at the end of the day, installing a cheap dedicated video card might be the way to go.
Click to expand...
So we would really like one or two of the video outputs to be SDI rather than HDMI. I see this card on Amazon. Maybe two of these cards?

Screenshot_20250709-133600.webp
 
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