To play video and audio files in formats such as DivX, Quicktime, or any other codec which isn't included in Windows by default, one might usually do one of the following. Install various codecs individually, or install codec packs that dump files wholesale onto your system and cause continuous crashes and slow downs.

A good option though, could be to uninstall all existing codecs, reboot, and install Vista Codec Pack. VCP is continu¬ally in development and pro¬vides defaults so as to allow for playback of almost all multimedia formats, while also keeping your system stable and CPU usage low, while playing.