Always meet this problem. Got audio but no video, any brother can help me.
Thank you so much!

What program are you trying to use to play the AVI file? Windows Media Player? QuickTime?

Have you tried this AVI file on another computer?

I have had this problem too, when I tried o play it on another computer, it worked...

Try uninstalling whatever program you use to play the file (Windows Media Player, possibly). Once it's uninstalled, use CCleaner to make sure your system is free of junk:

CCleaner - Home (http://www.ccleaner.com/)

Run a CCleaner "Registry" scan also and clean out everything it finds (make a backup just in case).

Once you've done that, reinstall the program that plays the file. Make sure it's the newest available version

Microsoft Windows Media — Your Digital Entertainment Resource (http://www.microsoft.com/windows/windowsmedia/default.mspx)

Just solve the problem. Install the codec full vision package and FLV player. Now can watch already.

For future views of this question

Install codecs

XP Codecs - K-Lite Codec Pack 4.5.3
Free-Codecs.com : Download K-Lite Codec Pack 4.8.5 FULL, K-Lite Codec Pack 4.8.5 STANDARD, K-Lite Codec Pack 4.8.5 BASIC : K-Lite Codec Pack is a collection of codecs and related tools (http://www.free-codecs.com/download/K_lite_codec_pack.htm)

Vista Codec Package 5.1.0 Final
Free-Codecs.com :: Download Vista Codec Package 5.2.9 : With Vista Codec Package installed, you won't need to install any other codec or filter. (http://www.free-codecs.com/download/vista_codec_package.htm)
Install with recommended settings

Vista Codecs x64
For users of Windows Vista 64 bit, first download and install the 32 bit package and then download the 64 bit extension from the link below and install that, then restart your computer and you will be able to watch any video.

Download the 32 bit package from here
http://www.softpedia.com/get/Multimedia/Video/Codec-Packs-Video-Codecs/Advanced-Vista-Codec-Package.shtml

Download the 64 bit package from here
http://www.softpedia.com/get/Multimedia/Video/Codec-Packs-Video-Codecs/VistaCodecs-x64Components.shtml

Installing these codec packs mean you will be able to use your Windows Media Player and even your Windows Media Center with any type of video (i.e. XVid/DivX) including Hi-Definition videos.

NOTE: Do not install any other additional codec packages or codecs apart from the installs shown or you may have problems, we have tested these packages for most video types and they appear to work perfectly.