I guess I'm the only one that had problems with CCCP. When I started using Windows 7 as a media player, I really wanted to use the Media Centre application because I have a pretty cool remote controller for it. The main problem was getting .mkv working with subtitles (ANIME!!) without too much hassle.
Long story short, I got everything working using Shark007 codecs. (http://shark007.net/) Give it a shot, it supports 64-bit even in some cases!