why am I unable to drag my downloaded library books to my nook color

[mariem23719494]

I have downloaded library books to editions 3.00

When I try to drag them over to my nook color I receive the following message

Errors were detected   No permission to copy the book

[elisabethv50094520]

I used to be able to do this. I had to switch to a different laptop, load digital editions, and now I can't get the digital book from the laptop to the Nook. Getting an answer to this issue is even more frustrating than trying to copy the book over.