I have downloaded the Divx 4 Codec & have encoded several Divx .Avi files using TMPEnc into Mpegs files. However, some .Avi's won't encode using TMPEnc, could it be that they are really Divx .Avi's in some format
other than Divx 4? Should I download like some other Codecs, which Codecs are the most common?

P.S. - Can you have more than 1 Codec on your computer at one time or will they conflict?

-Thanks-