How can I download my ebook from Adobe Digital Editons to my Nook? I am getting an error message that says 'Failed to write destination file'

I had the same problem with my Nook.  It only works with ADE 3.0.  Unfortunately, my computer automatically updates it to 4.5 every few days!!  What the heck.  So my routine now is to uninstall 4.5 and install 3.0 each time.  Annoying, but at least I know that works.