adobe digital editions have some very special characteristc of DRM. what exactly is done that if a file is protected by DRM, it can,t be opened on any other computer expect that one from which iit has been puchased. secondly file is expired after a certain period of time and no longer remain useable. I know there is some sort of dll file is used to crack it but I con't ind it any where. canm some body help me???????? I am astudent and have some books which are proected by this DRM.