If you're a Windows user, do a google search for "inept suite". This is an installer for everything needed to remove the Adobe Digital Editions DRM from Epub and PDF. You can then use Calibre to convert the DRM free books into whatever format your particular ebook reader likes. Of course, you should only do this with books you purchased and if one WAS to do this to books they downloaded from Overdrive you would be on the honor system to delete the converted files when your lending period was up.
