README

This script automates the process of switching your primary monitor with a dummy monitor using MultiMonitorTool.
This is useful for users of Sunshine (a screen sharing software) who experience issues with sharing their primary monitor.

Caveats:

If using Windows 11, you'll need to set the default terminal to Windows Console Host as there is currently a bug in Windows Terminal that prevents hidden consoles from working properly.
- That can be changed at Settings > Privacy & security > Security > For developers > Terminal [Let Windows decide] >> (change to) >> Terminal [Windows Console Host]
Prepcommands do not work from cold reboots, and will prevent Sunshine from working until you logon locally.
- You should add a new application (with any name you'd like) in the WebUI and leave both the command and detached command empty.
- When adding this new application, make sure global prep command option is disabled.
- That will serve as a fallback option when you have to remote into your computer from a cold start.
- Normal reboots issued from start menu, will still work without the workaround above as long as Settings > Accounts > Sign-in options and "Use my sign-in info to automatically finish setting up after an update" is enabled which is default in Windows 10 & 11.
The script will stop working if you move the folder, simply reinstall it to resolve that issue.
In the Sunshine WEB UI, make sure you leave the Output Name blank under the Audio/Video tab, otherwise it could cause breaking behavior with this script.

REQUIREMENTS

For GFE users

This script no longer supports GFE, but you are able to retrieve a legacy version of this script that does support it: https://github.com/Nonary/MonitorSwapAutomation/releases/tag/legacy

For Sunshine users

Version 0.19.1 or higher
Host must be Windows
Sunshine must be installed as a service (it does not work with the zip version of Sunshine)
Sunshine logging level must be set to Debug
Users must have read permissions to %WINDIR%/Temp/Sunshine.log (do not change other permissions, just make sure Users have at least read permissions)

INSTRUCTIONS

Open up MultiMonitorTool and click on File -> Save Monitors Configuration and save it in the current folder this script is located in with the name of primary.cfg.
Repeat the same steps of step 1, except save it with the name of dummy.cfg.

Open up the dummy.cfg file and set every parameter related to your primary monitor's position, refresh rate, etc. to 0. For example:

 Name=\\.\DISPLAY1
 MonitorID=MONITOR\GSMC0C8\{4d36e96e-e325-11ce-bfc1-08002be10318}\0009
 SerialNumber=LGTV
 BitsPerPixel=0
 Width=0
 Height=0
 DisplayFlags=0
 DisplayFrequency=0
 DisplayOrientation=0
 PositionX=0
 
 Name=\\.\DISPLAY11
 MonitorID=MONITOR\XMD29831\{4d36e96e-e325-11ce-bfc1-08002be10318}\0007
 SerialNumber=DUMMY
 BitsPerPixel=32
 Width=3840
 Height=2160
 DisplayFlags=0
 DisplayFrequency=120
 DisplayOrientation=0
 PositionX=0

In the example above, every numerical value has been set to 0, which lets the script know that the display should be turned off.
Also take note in the example, that my dummy display should have values configured to let it know that it should be turned on.

Verify that the dummy.cfg file has only one display that contains values for the BitsPerPixel, Width, Height, and so on.
4a. For the primary.cfg file, it does not matter if there are other displays enabled, but you would want to make sure your dummy is "zeroed out" so you don't end up with an invisible monitor.
Basically, primary will "zero out" the dummy plug, and dummy will "zero out" the main display. This will automatically transfer games and windows back to the primary monitor if setup this way.
In the primary.cfg file, locate your primary MonitorId and copy and paste it to the primaryMonitorId key in the settings.json file. Make sure to escape the backslashes.
In the dummy.cfg file, locate your dummy MonitorId and copy and paste it to the dummyMonitorId key in the settings.json file. Make sure to escape the backslashes.

Validate you have escaped the backslashes, below is an example of a valid settings.json file.

{
"startDelay": 2,
"gracePeriod": 60,
"configSaveLocation": "%TEMP%",
"primaryMonitorId": "MONITOR\\GSMC0C8\\{4d36e96e-e325-11ce-bfc1-08002be10318}\\0009",
"dummyMonitorId": "MONITOR\\XMD009A\\{4d36e96e-e325-11ce-bfc1-08002be10318}\\0010"
}

Install the script by double clicking the Install.bat file, you may get a smart-screen warning... this is normal.
You will be prompted for administrator rights, as modifying Sunshine configuration will require admin rights in the coming future.
Verify that the sunshine.conf file is configured properly, if successful the global_prep_cmd should look like this
global_prep_cmd = [{"do":"powershell.exe -executionpolicy bypass -file "F:\sources\MonitorSwapAutomation\MonitorSwap-Dummy.ps1"","elevated":"false","undo":"powershell.exe -executionpolicy bypass -file "F:\sources\MonitorSwapAutomation\MonitorSwap-Functions.ps1" True"}]

The paths referenced above will vary on your machine.

TROUBLESHOOTING

If you encounter issues with the script, you can try the following:

Check that your primary monitor MonitorId matches the value in the primaryMonitorId variable in the settings.json file.
Check that your dummy monitor MonitorId matches the value in the dummyMonitorId variable in the settings.json file.
Check that you have escaped the backslashes in both the primaryMonitorId and dummyMonitorId in the settings.json file.
Valid: MONITOR\\GSMC0C8\\{4d36e96e-e325-11ce-bfc1-08002be10318}\\0009
Invalid: MONITOR\GSMC0C8{4d36e96e-e325-11ce-bfc1-08002be10318}\0009
Check that you have set every parameter related to the primary monitor's resolution in the dummy.cfg file to 0.
Check that you have set every parameter related to the dummy monitor's resolution in the primary.cfg file to 0.
Check that you have at least one monitor not "zeroed out" in both the primary.cfg and dummy.cfg files.
Ensure that you have followed the requirements for Sunshine users as listed above.
Increase the startDelay in the settings file if you're experiencing the script only works intermitently.
If you are still experiencing issues, try uninstalling and installing it again.

Recent Changes

Fixed a bug that caused the script to stall out Sunshine that could not be recovered until restarting the service.

Nonary/MonitorSwapAutomation 1.0.4 on GitHub