When you try to open a file that is not associated with any of the software, Windows will display an app picker UI. Through the “How do you want to open this file” window, users can select the app through which the file should be opened.
The current app picker UI in Windows 10 and Windows 11 looks like the below.

In the latest Windows 11 Insider build, Microsoft is testing a new app picker UI that aligns with Windows 11’s overall look and feel. As you can see from the screenshot below, the new app picker looks better and also allows users to easily set an app as a default app for a file type.

Here’s how you can enable this feature in Windows 10 Build 22563:
- Download ViveTool.
- Execute this command as Admin:
vivetool.exe addconfig 36302090 2
. - To disable this feature, execute this command as Admin:
vivetool.exe delconfig 36302090 2
.