The following link is Ineptkey.pyw 4.3. It is what you need to generate the adeptkey.der file with the new Adobe Digital Editions 1.7.2.
Using the Python GUI, also called IDLE, open the ineptkey.pyw file and then under the RUN tab, hit the RUN MODULE command. This should get you the Adeptkey needed to break the adobe adept drm on epub files. The file created should automatically save under the python26 directory and be named adeptkey.der.
Then you need to run Ineptepub.pyw. Instructions and download included in the linked post.
and remember, please click on the code tag to see the other posts about DRM removal.