why cannot play some avi files

[qilst3]

I got some avi files that I cannot playback. I installed both Divx4 and Divx5 bundles, but it seemed neither worked. There are only sounds and black screens. Any help? Thx!

[sirius]

Open the file in VirtualDub ( www.virtualdub.org ) and then if:
a) an error message appears, post back the exact text.
b) the file is successfully opened, open the File-> FileInformation and post back the video format indicated.