Compressed/uncompressed the only difference is code for files/images and the quality of the images, i highly doubt it would affect you being unable to play, Remember to save after the last decision in day 2, if you cannot see start chapter 2 or whatever its called, go preferences and click start new game... Chapter 3 can have a problem, still you just started playing, so just get the day 7 (chapter 3) it has 5,6 and day 7. People had trouble loading after last decision in day 6 for day 7 but it was easy worked around by choosing a file/save before the last decision in day 6... anyway just remember to save after the last decision and then start the 3-4 release and play and if you don't see blah blah i am repeating myself ...