divx 3.11 and other codecs

i have divx 3.11 installed on my win 2000 pc,my problem is i need to install the new divx 5.02 codec.is the 5.02 codec/player downwardly compatable with the 3.11 codec?.i use media player 7.1 to watch files encoded with the 3.11 codec.can anyone tell me which codecs 5.02 supports,and what i need to do to use/install the 5.02 codec.ive looked throughout the forum but cant find an answer.thanks for any help recieved.

Nice Search Buton 

You see the nice search button in the upper bar, try it! Anyways search for FFdshow the best decompressor for MPEG4, and all your problems are gone!