hey guys, i literally got my macbook a few hours ago and i've been trying to get some studying done on it but i can't seem to open pdf files. i read somewhere that preview should do the trick but i keep getting this message "The document IMMUNO 2008 CHAPTER 6 PART III.ppt could not be opened. The file is not in the right format." i even downloaded adobe reader and i still get the same message. the same exact files work on my old laptop that runs xp. i have no idea what to do at this point. please help!