We show you multiple ways using which you can change File Type.r Extensions or Format on Windows 11/10. You can also use the Command Prompt.

It’s also helpful to quickly identify and change file types when needed. To show file extensions in Windows 11, open File Explorer, navigate to View > Show, and select File name extensions.

If you can't change default app by file type in Windows 11/10, then reset the problematic app, remove file type association, etc.