Unknown audio format

Audio not working for DivX 7.2.0. Message pop-up says - This file contains an audio track in an unknown format. You may need to install DirectShow Decoder.... How do I go about doing this?
Please help

No magic bullet on this one. Use gspot (http://www.headbands.com/gspot), feed your file into it, and find out which audio codec is needed.
If it’s AC3, get the AC3 filter.