I downloaded some instructional videos and they are in MP4 files. My knowledge of video formats doesn't go much past - 1. download video. 2. click start button. 3. watch video. Apparently my computer doesn't know what to do with them. What do I do with an MP4 file? I downloaded one player that looked ok, but when I read the user agreement, it was saying things about giving information about me to other companies so I deleted that one. Is there an MP4 player (preferably free) available to download that anyone would recommend?