Originally Posted by chaley
Out of the box, calibre does not strip DRM, and K4PC does handle DRMed books. Either the books you got from Amazon are free of DRM-infestation (some are), or you are using one of the DRM-stripping tools available (that we can't discuss discuss further on MobileRead).
I'm not using any add-ons for Calibre, so I must have picked a book with no DRM. I didn't know Amazon had books with no DRM.