ADE freezes each time try to download a book

I downloaded ADE 3.0 because the upgraded version does not work. But this one freezes each time I download a book. And I have not managed to download more than one or two after shutting down my computer each time! I need ADE specially for .ascm extensions books so as to download it on my Kobo nia reader. Can anyone help?! I have been on this for days! I have desauthorised and reauthorised, unistalled and re installed...