I had Adobe Digital version 4.0 on my laptop to use with my Nook. I just started not being able to open public library books on the Nook. Contacted Barnes and Noble. They said that I needed Adobe Digital version 2.0, nothing higher to use with my Nook. Uninstalled version 4.0, installed 2.0. Now I need to have the version 4.0 deauthorized from my computer and the version 2.0 activiated. Can someone help me, please?