I had mp3tag 2.37f installed on my WinXP pro machine. I could right-click on an mp3 or flac file and load that specific file into mp3tag.
However, I have recently reinstalled WinXP and mp3tag 2.37h. I get the mp3tag context shell option on a folder, but not on a file/group of files.
I've hunted through all the program options and can't see a way of adding the shell context option. I don't remember seeing any option when I installed. Have I missed something?