By what information are applications grouped in Windows Taskbar

Question

I have a WPF application that has two builds, one is beta and another is stable .

The user can have both of them installed at the same time, each within its own folder in %localappdata% ( %localappdata%\app-name and %localappdata%\app-name (beta) .

When they are both installed at the same time, Windows groups them on the taskbar as if being the same application.

So, the apps are not binary-equal, they reside in different directories and they do not have the same title. But there's obviously a piece of information that's shared between the two apps which is what Windows uses to determine how to group the apps, but I don't know what piece of information that is.

What is that piece of information which I need to change for one of them so that they can be properly distinguished by Windows in order for each to have its own taskbar item?

Answer 1

The GUID in assembly info:

You should create a different GUID for each version https://learn.microsoft.com/en-us/do.net/api/system.guid.newguid?view.net-7.0

Answer 2

The taskbar grouping is based on the Application User Model IDs (AppUserModelIDs) . If you don't specify one then Windows will generate one for you using undocumented details.

You can p/invoke SetCurrentProcessExplicitAppUserModelID to set a specific one for the whole process. It is also possible to set one per window.