Force combinig icons on taskbar for windows form applications (C#)

Question

I have a problem with combining icons for instances of my application in taskbar.

For some users it combines without any problems and others see new button in taskbar for every instance of my windows forms application opened (although they have "always combine" in taskbar settings).

Is there a way to force combining icons of my application programatically? What property decides that windows recognizes instances of my application as similar or not?

Answer 1

As I understand it it's based on the weather the additional "things" are spawned as a process from the same executable.

I don't think there's a way you can enforce this grouping behaviour. But you could ensure clients have the start menu property set to combine buttons by Group Policy. In:

User Configuration\\Administrative Templates\\Start Menu and Taskbar\\Prevent grouping of taskbar items

Source link for Group Policy settings: https://technet.microsoft.com/en-gb/library/ee617162%28v=ws.10%29.aspx