Windows Essentials Codec Pack is a collection of the most essential Audio and Video DirectShow Codecs and Filters. With Windows Essentials Codec Pack you should be able to play 99% of all movies and music files that you download off the internet, stay up to date with the latest Codecs with the Audio / Video Codec Update Service, and eliminate the many conflicts and error caused by using multiple codecs to decode the same file types.
W.E.C.P. is designed as a user-friendly near complete solution for all your video and audio needs, with it you can play Audio CDs, DVDs, (S)VCDs and XCDs on the fly, and it adds support for 3GP, AAC, AC3, APE, AVI, DivX, 3ivx, DAT, h.264, x264, Nero Digital, DTS, FLV, FLAC, HD-MOV, MPEG-1/2, M4A, MP3, MP4, MO3, MOD, MKV, OFR, TTA, OGG/OGM, S3M, Vorbis, VOB, XviD, XM, WV, UMX and many more formats so you could play any video / audio file with your favorite DirectShow media player or with the (included) free and wonderful Media Player Classic
