Newbie can't get started adding tags

I'm just starting out, so I think I might have a basic problem with my settings or something else.
I have a Dylan album copied from vinyl. The files are AIFF. They show the names of songs, the size of the file and the filename, but not the name of the album or the artist.

I used Discogs to add Album and Album Artist, but when I save nothing happens with my original files. I've also used the tag panel to put Bob Dylan in Artist field, but that doesn't work.

I've followed the procedure outlined in the FAQ several times, but I'm stumped. I might have a settings or a mapping problem, I think.

After you have entered the data in the tag panel, you have to press Ctrl-S or click the save button in the toolbar to save the modification.
As far as I can see, MP3tag shows the tags.
The other question is whether the Windows Explorer can cope with AIFF files (which I doubt).