First, I'm sorry if this isn't the right forum for this question! I'm afraid I don't know much about this sort of stuff. After I formatted my hard drive a couple months, I haven't been able to play most mpeg files. I was able to before, and I can't figure why they're not playing because I have all the same players as I had before. I keep getting errors like... Windows Media Player says "class not registered", RealOne just gives me an illegal operation and closes, Winamp doesn't do anything at all, Quick Time says it's missing software. The players also give me those same errors when I try to play this one avi file too. I can't find any info on the net about this problem! I'm guessing I'm missing some sort of codec...? But I have no idea which one I need. Can anyone help??