Duplicate files?

augeydoggy  wrote I am using PSE 18. In my main Photo directory I have the usual accumulation of jason files, but also lots of other apparently duplicate jpg, raw, mov files. All of these have a file name beginning with B. Are these some sort of backup, and are they  necessary?

Those files beginning with B are typical of a backup folder. Usually those folders are created on an external drive. First look, at the name of the folder and see if it can be a backup made by error on your main drive. A backup folder also contains two important files: catalog.buc and backup.tly. If this is really a backup folder, you should delete it or move it after creating a new full backup on an external drive.