Are you experiencing low volume while playing divx or xvid clips or movies? This is a problem with clips or movies encoded with the ac3 codec. The default sound volume is really low. Forgetting to lower the volume while changing between divx/xvid and dvr-ms movies can really annoy your neighbours and scare the **** out of you.
How to increase ac3 volume? Download ac3 filter and install. Start ac3 filter config in your start menu / All programs.
Increase "master" slider and press ok. Restart your computer to apply the changes.