There is a much simpler way to work it that continually making a folder in each new course when you are using pics in more than one course on the same server/moodle install.
I teach both web and multimedia classes using Moodle for quizzes and lessons.
Both classes covered Internet history which had some pictures.
I made a folder called internethistory inside the moodle directory and upload all pictures to it.
Questions link to /moodle/internethistory/filename.filetype
Now regardless of when those questions are used in web quizzes or media quizzes - they find the pictures automatically.
Large moodle servres- make folders called by teacher name instead of internethistory or even get sophisticated
/moodle/teacher_name/course_name/picname.pictype
once teachers learn when they put their images , the path setting when editing questions is easy.
to move to a new server - one would not only have to back up the quiz(zes) but also copy the images folder and place it at same location on the new server. Not the easiest maybe - but 100% effective long as the images folder is not tied up with permissions and who can use it and who cant.
This has been my salvation this year with questions being shared between my web and media classes or between my Computer Science I and II classes.
Hope this helps
Louis
Andrews High School
Andrews Texas