Hi Emma, Firstly, don't buy books with DRM. With DRM you don't own the book - you're at the mercy of the publisher and the eReader working together. At any point, the publisher could stop your book from working. On a more practical note, you have three options. 1) Complain to the shop where you rented the book from. 2) Find a way to break the DRM. That may be illegal, depending on where you live. 3) Delete the book from your eReader, delete your eReader from the Adobe software, then re-add them. That should work. If not, ask for a refund. Remember, DRM doesn't work. It is designed to break and to be inconvenient to you. Hope that helps, T