When dealing with codecs, more does not equal better. Having the least amount on your system is the best configuration. This is exactly what the Vista Codec Package does for you.
Below the is the official change log for Version 4.5.4 :
- add shortcuts for broader MKV playback
- add shortcuts for mpeg2 decoders (.ts)
- update ffdshow 1604 (mutithreaded h264)
- improve RealMedia browser support
- remove all QuickTime components
- maintain MOV and 3GP playback without QT
- offer QuickTime Lite for VCP separately
You may download this new version here.