The 'File Properties' window is provided by the Windows® operating system. The actual tags in the music file can be viewed and edited from the 'Details' tab. Not all file types support all the tags, so which tags are shown depends on the file's type.
This window can be opened from the Music Library Manager for the selected track by pressing Ctrl+Enter, or by using the context menu command 'Library Management > File Properties'. You can also open if from the Windows' File Explorer's 'Properties' context menu command.
Note! If you change the tags from the 'File Properties' window, it will NOT update the Music Library Manager database. Likewise, changing the Track Properties using Music Library Manager will not update the tags in the music file because it never makes any changes to your music files. Music Library Manager reads the tags only when you Import the files.
Tips: If you really want to change the tags or the album art in the music file, you can use the Export command to create a new file containing the new tags, and optionally insert the album art. You can also update or correct the tags when you Import the music files.
Always close the window afterwards, because Windows will open a new 'File Properties' window every time, in exactly the same place, so you don't notice it. It can take a long time to close them all, and the pub may be quarantined by the time you're finished.