Hey, you have to specify what kind of hardware you have to ask some kinds of questions, because some files are only playable by some softs. For instance, a dmg file is a disk mount file (whatever that is) only usable by macintosh (I think). A sit file is a kind of zip file unzipped by a program called stuffit, and since I have an iMac, I can't tell if your regular Windoze unzip program will open it.