Ok this is a really stupid question but since I cannot find the answer I guess I have to ask. I have a file with an avi file extention. How do I find out what kind of file it is (I suspect that it is divx 3). Is thier a program that can look at a file and determine what it is? Second, how do I find the right codex? At least one program that I use to try to convert it said that it was divx 3 but I went looking for the codex and thier are diffrent versions (specifically 3.1 alpha and 3.22b are ones I found).

On a side note, does anybody know a a good (hopfully not to hard to understand) website/guide or whatever where I could read and learn more about codexes and avi file formats?

use Gspot to ID the codecs: http://www.headbands.com/gspot/

articles about codecs: http://www.divx-digest.com/articles/index_english.html

obviously doom9.org (which is currently down but here's the forums: http://forum.doom9.org/) and afterdawn.com (http://www.afterdawn.com/guides/)

Thanks a lot!! That should give me some good reading material to get it figured out/learn more about it.

no prob...good luck with it. i'm sure others here are very knowledgeable with this stuff and can lend a hand if you've got something specific in mind. i know some basics but am still a relative noob with the codec stuff.

One thing to avoid doing is downloading one of the multi-codec packs. You just don't know what will get installed/overwritten.
Try always to dl just the ones you require.
Two other apps that are very handy are Avicodec ( http://avicodec.duby.info/ ) & Video Inspector ( http://www.kcsoftwares.com/ ).