How to change monitor assignment in a dual monitor environment

So I know this is has long been answered. But I found out that the specific answer is incorrect. Microsoft's monitor display numbering system depends on which hdmi slot you hook your monitor and tv into, how it reads the drivers for the monitors and loads how the NVCP (nvidia control panel) is set up.

Let's use the an example of dvi. If there are two dvi slots. A dvi-d and a dvi-i. Dvi-d is below the Dvi-i. If you have your main monitor connected to DVI-I and then hook up your secondary display to DVI-D, windows will re-order the display numbering. Window's defaults the display 1 to DVI-D not DVI-I. So if a secondary display such as a tv is hooked into the DVI-D slot on your graphics card, windows will make that the display 1. Your computer monitor then becomes display 2.  This is because this is how the default settings were set in the NVCP.

This is the same concept with your HDMI slots. If your tv is hooked into HDMI and your monitor is DVI graphics cards windows reads HDMI as priority in dual monitors.  Now this is the tricky part. Graphics cards for some weird reason read TV's as priority by default. Even if the TV is hooked from HDMI to DVI, the TV will get priory. Priority for pre-windows like bios screen gets put on TV's for some reason. 

If both displays are hdmi or both displays are DVI, then windows will read the output closest to the motherboard as display 1. This means that you have to swap slots. This is the easiest way if you don't want to bother messing with the settings in the NVCP. However if that doesn't work,  you can change the display numbering order in the graphics card settings, using NVCP. Nvidia graphics cards have the Nvidia control panel software come with the graphics card. It's not very hard and you can rearrange priority of your display output slots.  If you use on-board motherboard display, then you might have to tamper with the motherboard bios settings for display.  It's tricky but it's usually a graphic's card issue reading monitor displays.

If you have an ASUS brand of nvidia graphics cards don't expect too much help. ASUS has horrible customer service.

The monitor behavior in Windows 8.1 in baffling.  There are 3 total monitors connected to the system.  An LG tv, an Acer and a BenQ.  The LG is connected via HDMI, the others are connected via DVI; all are connected to an AMD 290X graphics card.

Every time the system goes to screen saver it moves all my windows off of the monitor marked as "main" and puts them onto my LG tv that is connected via HDMI, which shortly after turns itself off because it isn't receiving input.  If I'm lucky enough to have control panel open on the Acer monitor (where the windows don't magically move) I can disconnect the LG to get the windows back to the main monitor, only instead of moving them back to the BenQ (Monitor 2, main monitor) where the windows were originally opened, it moves the windows from the Acer (Monitor 3) to the BenQ, and the windows from the LG tv to the Acer.  Its like they are playing a game of musical chairs with my monitors.  It doesn't even make sense and there doesn't really seem to be any rhyme or reason to it, which I think is at least equally frustrating, maybe more.  It doesn't happen at the time the screen saver comes on because if I'm in front of the computer and give some input to exit it isn't an issue.  This means the only other likely time is when the tv shuts itself off... You read that correctly... it moves all my open windows on to a monitor with no power.  The LG monitor is identified as monitor "1" which shouldn't matter, but I'm sure it plays a role.  The BenQ is assigned to monitor "2" and the Acer is monitor "3".  I've been running Windows 8 for probably 4 years with the exact same setup as far as the monitors go and this has only recently become an issue despite no changes to the hardware in the last 6 months to a year.  The only thing that has changed, is this is a fresh installation of Windows.

I've scoured search results on this issue and nobody seems to have an answer.  The "Microsoft fix-it link" provided earlier in the thread resolves to a "Page Not Found" 404.  I saw another thread where a Microsoft representative referred to it as a "feature".  Moving all my open windows (which can easily number 20-30) to a monitor that isn't even powered on and isn't in plain view from my main monitors is not a feature; its an extreme annoyance.  It takes me 3-4 minutes just to drag everything back every time this happens, which is several every single day.  Tricks like the "Cascade Windows" trick to pull the windows back onto the main monitor don't work.  Closing them while they are open on the LG screen results in even more unpredictable behavior;  the next time I open the program, it might (*might*) open on the LG screen.  I'll tell you what would be a feature though: An operating system that didn't believe it was more capable of handling window placement and managing monitors than the user.

I'm adding my vote for Microsoft to fix this issue.

On my dual screen setup...

19" acer monitor is set my primary display via DVI and was assigned #2 in Windows.

24" HDTV is set as my secondary display via HDMI and was assigned #1 in Windows.

If I press Win+P it says my 24" HDTV is my PC screen and my 19" acer is my second screen.

No amount of tweaking or disconnecting or deleting or disabling or dancing around fixes this.

MS techs... Please let us switch numbers 1 and 2.

Edit...

This is on Windows 10 with an Nvidia GTX750Ti graphics card. I've read elsewhere that graphics cards assign the displays starting from the topmost video output, which makes sense because the GTX750Ti has in order from top to bottom... Displayport, HDMI, and finally DVI. For kicks and giggles I bought a displayport to DVI adapter and plugged my acer 19" monitor into that instead of the previous DVI, and it correctly identifies as #1 (PC screen) in Windows, and my TV is now correctly shown as #2 (second screen).

It has to do with the number of graphics drivers and the way that those drivers enumerate attached displays.  The system starts with the driver for the embedded graphics ( i.e. Intel ), then proceeds to the discrete graphics, if present.  If there are no monitors attached to the embedded graphics then it's only dependent on the enumeration from the discrete graphics driver.  If you want a different order, play around with which monitor is physically attached to which port ( DVI1 vs DVI2 vs HDMI ).  Hope that helps.