Well. Thanks. However, I think I do read a lot of things related. The point for me (and maybe lots of other newbie) is that it is kind of hard to figure out those professional words and what my problem really is. And to make things worse, xvid changes very fast and lots of out-of-date information mixes with the correct ones in this forum. For example, I did read some stikys here which said ffdshow is the availbe good decoder. Anyway, thanks for all your help. I found this forum is especially helpful.