I have posted everything I could find on your product on our wiki
EZ Reader T778. It is nothing like the Astak version of
EZ Reader. What does the manual tell you to do? First effort would be to try a non-DRM product to see if it can read ok. There are lots upload in our eBook section. Try a ePub book. If that works we can proceed from there. Feel free to update the wiki if you have more complete information.
Dale