Don; to get a version of the book that is useful in other readers, or on DropBox, you need to go to the Kobo website
www.kobobooks.com and head to the My Library tab. Here you will find the option to download an ePub version of your books.
This actually downloads an ACSM file that when opened via Adobe Digital Editions (ADE) will download the real ePub. This will be store in Documnets\My Digital Editions and is protected via DRM. We can't discuss here how to remove DRM; all we can say is google "Apprentice Alf".