Vista Codec Package is a free codec pack (freeware) for Windows Vista, Windows XP, Windows 2003 and Windows NT. With Vista Codec Pack package installed, you won’t need to install any other codec or filter. The codec pack combines all the best and popular codecs available in the world.
The author also tracks down the latest updates to the codecs used in the pack, and tests their functionality before been updated and included in the package, plus resolve all possible conflicts.
The official change log for version 4.7.3 is as follows:
update ffdshow rev 2080
update Gabest filters rev 729
improve M2T support in Vista WMP11
Fix audio in MKV some other audio formats too
remove PLS support (see homepage Tools section)
remove SPDIF config tool (see homepage Tools section)