If you've ever come across a media file that wouldn't play in your media player, this is the answer to your needs. It installs the codecs--short for coders-decoders--that your media player needs in order to play back many different kinds of media. For the techies out there, here's the list of what it handles: 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, AVC, Nero Digital, DTS, FLV, FLAC, HD-MOV, MPEG-1, MPEG-2, M4A, MPC, MP3, MP4, MO3, MOD, MKV/MKA, MTM, OFR, TTA, OGG/OGM, S3M, Vorbis, VOB, WavPack, ATRAC3, XviD, XM, WV, and UMX.