It’s really hard to make much sense of your question and the comments of others, because they seem to conflate three distinct aspects of ICC profile usage.
The three aspects are:
- Display (i.e. Destination) profile.
- Display calibration curves, saved in the Display profile.
- Source Profile.
For MSWindows systems, the Display profile should be (put) in the standard system location, and color managed applications should be using it from that location.
Installing using ArgyllCMS/DisplayCAL will put display profiles in the standard location. I don’t know enough about darktable to know if it picks up the display profile from that location. If not, it should!
Typically when you create a display profile you also do a calibration. Those calibration curves need to be loaded into the graphics card hardware for the display profile to be valid. Modern MSWindows system have the ability to do so for the display profile, or a display profile loaded program could be used, such as ArgyllCMS’s dispwin. This may also be useful in figuring out what & how to make sure calibration is loaded.
When an application uses color management, it needs to have two ICC profiles specified for an image, a Source profile which describes the color space the image is in, and a Destination profile. Typically the Source profile will be either tagged in the image and/or be something selected by the user from a menu. Typically for displaying on the display, the Destination profile is the system Display profile.
To get color management working, you at least need to be clear that these three aspects are setup correctly.