Let's just say its far from automagic. But if a video file fails it could be that Microsoft has blocked the codec, the codec doesn't work with WMP or "other."
To work this issue I might try GPSOT CODEC APPLIANCE (use google when I offer no links) and I might use VLC PLAYER to play the content instead of spending time on WMP.
Ive just downloaded the codec pack from the site to play different file types but what do I do now ? I thought it would autmatically integrate with Windows Media Player but it doesnt so what do I need to do to get WMP to use the codecs ?