If you go into the BIOS/UEFI settings, is there one for "primary display
adapter"?

https://ibb.co/album/NdbMCD

That shows you are using the integrated (onboard) graphics controller
inside the CPU. When you boot, the onboard video gets used. Any video
adapter in a PCI-e slot will not get used.

Are the cables to the monitors plugged into the backpanel video ports,
or into a video card's ports? You mentioned "NVIDIA GeForce GTX 750
Ti", so I figured you were using a video card, not onboard video.

This is what I saw with both onboard and video card (not at the same
time obviously) when physically video cables. I am more amazed that W10
will autoswitch between them without rebooting. So I can use Intel or
NVIDIA right away after switching video cables.


iGPU = integrated GPU (inside the CPU, so onboard video)

Most times when you have iGPU enabled in BIOS, that means to use the
onboard video, and a video card, if present, is not used. And disabling
iGPU (onboard video) is required to use the video card in a slot.

To which ports is the VGA monitor connected? Which ports for the HDMI
monitor? There will be backpanel video ports for onboard video. If you
have a video card installed (GTX 750 Ti), it has its own video ports,
and some video cards allow multi-monitor support.

According to the Asrock manual, "Supports up to 2 displays
simultaneously". It has D-Sub (VGA), DVI-D and HDMI. Do you have both
monitors going to the backpanel ports for onboard video?

Yes. I even disconnected them and connected to the video card.


From pics for the MSI NVIDIA GeForce GTX 750 Ti, it has D-Sub (VGA) and
HDMI ports. Some custom models have 3 ports: D-Sub/VGA, DVI, and HDMI.
Some models (the extra thick ones that fit into 1 PCI-e slot but occupy
the width of 2 slots) have 4 ports: D-Sub/VGA, DVI, DP (DisplayPort),
and HDMI. nVidia GeForce GTI 750 Ti only supplies the base or reference
model for the video card. Different makers can decide to either deliver
just the reference model, or use extra features on the PCB (which would
require more chips; else, you see empty solder pads), like a different
port count. I found 2- and 3-port models of MSI's implementations of
that reference card, but not a 4-port model (I didn't look that hard).
At the MSI site, searching sucks: "GTX 750 Ti" returns results for other
models. Using a Google search, I did find:

https://us.msi.com/Graphics-Card/N75...-specification

which is a 3-port model: D-Sub/VGA, DVI, and HDMI. So, are both your
monitors connected to the video card? Or are you trying some mix with
one monitor using onboard video (backpanel video port) and the other
monitor using the video card? You say you're using a video card, but
you show the BIOS still has onboard video enabled. Could be the BIOS is
smart enough to disable onboard video if it see video BIOS get loaded,
but I think it'd get confused if you left onboard video (iGPU) enabled
while one monitor was on iGPU but the other monitor was on video card.

With a video card, iGPU should be disabled in the BIOS, and the video
card configured for multi-monitor support (attach both monitors to the
video card, and use nVidia Control Panel to specify order). I suspect
the priority order isn't obeyed until the nVidia driver gets loaded
which will be after Windows loads. My guess during boot (and before the
OS loads) that the latest tech port gets used for the primary display:
HDMI, DP, DVI, then VGA.

This is what I am noticing. I don't see anything on my VGA screen until
W10 is loaded at the login screen. I never see the UEFI, its CMOS and
POST, and W10's startup splash screen if I have HDMI connected. If I
disconnect the HDMI, then everything will show up correctly on VGA monitor.


Have you looked at nVidia Control Panel's "Set up multiple displays" to
see what they let you configure there?

http://i10.photobucket.com/albums/a1...ps0923cca5.jpg

Yes. It's like W10's display options. Both show VGA connected monitor
is as display #2 while HDMI connected HDTV is #1. I want them
reversed as in VGA monitor as #1 while HDMI HDTV as #2.

The screenshot to which I linked shows you can rearrange the display
order. In the nVidia Control Panel, did you try dragging the icons to
change the display order?

Yep. It still makes my HDMI HDTV as #1 and VGA monitor as #1. I just
want to change them in and out of W10 when HDMI cable is connected.


Windows 10 display settings let you select multiple monitors, but I
don't know if the "Make this my main display" lets you select which one
is the primary display. nVidia's Control Panel should. That's what the
bottom half of that dialog shows is icons for each monitor, and you can
drag the icons.

They both do let me say primary display, but still won't change the
numbering. https://imgur.com/a/Wj30oYp for my dual and single display
setups showing my desktops with NVIDIA and W10's settings.


Can you select a monitor in Win10's multi-display dialog, so it has
focus when you click on "Make this my main display"? If that doesn't
work, have you tried using nVidia's Control Panel to drag the icons to
rearrange priority order?

Yes. I just want to change their numbers.
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