OK, calm down,
I have no idea what all that stuff means but there's a few things I'd do if I couldn't open a video file,
first I'd try opening it in Virtualdub (google it, it's free and excellent), this will normally do the trick, you can play it back in there, or export it as an .avi,
if that doesn't help, it could be the files corrupt, if so download it again, or put a comment up about it to see if anyones fixed the problem where you Dl'ed from.
also try opening the file in something that'll give you the codec used, a program called G-spot does this I think, but loads of editing apps will tell you if you look for properties of the clip, then download the latest version of that codec.
if nothing works, I expect you can get a copy of the video file from another source off-line if you really need it.