I was given a DVD(+RW) made for us that we watched using a hardware DVD player, and we're unable to open the DVD in Windows XP. Explorer is very slow to respond, and eventually (after several minutes) shows only a blank window. The person that recorded the DVD from a digital camera download says that he used Windows Vista to create the DVD. What kind of filesystem might this be? UDF? Compressed UDF? ISO9660? Might the owner have accidentally included some sort of copy protection that precludes viewing the directory structure? The DVD won't even play in XP, although it plays on a normal hardware DVD player with output to a television screen. Maybe the DVD+RW wasn't "closed" after writing, or some such thing?