Problems with playing avi file - how to determine exact codec? I'm totally new to this. I just downloaded a movie. Absolutely no idea how to run it. I'm on Windows 2000, and as far as I know, I don't have any codecs. Thanks for the help. You might want to look into AVIcodec and GSpot. Although GSpot is generally more informative, AVIcodec gives you the direct link to codec. AVICodec: http://avicodec.duby.info/ Download GSpot: GSpot260b01.zip Also, if GSpot tells you that the FourCC code is 0 then you most likely have a fake! You can try running the movie through AVIFix or DivFix -- remember to make a backup first because sometimes it makes it worse!