I am trying to figure out how to control the Win+P project options so they can be configured to work as desired. I found this identical question from several years ago that was never answered.
My system has 4 displays connected to a GTX 1070. I would like to have the "Second screen only" option from the Win+P menu enable monitors 1 and 3, and have the "Extend" option enable all 4 monitors. I know this is possible as it was working just like that. I recently disconnected my system and pulled the GPU to do some dusting, and even though no changes were made, the "Second screen only" now enables monitors 2-4 instead of 1 and 3. This is not the fist time I have run into this change, unfortunately last time I did not note exactly the steps I took to fix it, as it was mostly luck.
I am aware of DisplaySwitch.exe and the different command options, but that is just the executable the Win+P menu calls so it functions no differently. In my efforts to find a way to control which displays are chosen for the different options, I have been looking at the registry at "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers\", specifically under the keys "Connectivity" and "Configuration". Both of these contain a list of my 4 displays as well as all the permutations of them combined (see screenshot). Configuration looks to store the values of the display resolution, XY position, color settings, etc. Connectivity appears to be the one I am after, as it contains the values "Clone, eXtend, External, Internal, Recent, SetId" which match the options for DisplaySwitch.exe.
I deleted all of the keys under Connectivity except for the one that contains all 4 of my displays. I then changed the value of "External" from "DELF043FJ44J46L886S_19_07DE_4F+ACR06D72232435078_33_07E2_5E+DELF042FJ44J46L633S_19_07DE_DA" to "ACR06D72232434730_33_07E2_AD+ACR06D72232435078_33_07E2_5E" with the hope this would change which screens were selected. This does not seem to work, as calling Win+P reverts the registry value back. Rebooting also reverts the setting.
My question, where can I find the setting/registry value that controls this? I realize it's a niche thing, but I used it so much, not having it is really a drag.