When you first open the program there are 5 or 6 files already highlighted. Do i only need to decrypt these files or should i highlight everything?
It depends what you are trying to do and what software you are using. For most purposes all files should be selected. Tools > Settings > File Mode > Select Files: All. If you are just backing up a single layer DVD-5 disc then just use. Mode > ISO > Read Then Mode > ISO > Write If you are backing up a duel layer DVD-9 disc and using DVD Shrink then use. Mode > File Or Mode > ISO > Read DVD Shrink can open either of those types. Of course in most cases you directly rip starting with DVD Shrink and do not need to start with DVD Decrypter.