I was searching for a way I could view media files recorded on my Vista machine (through Media Center) and found this beauty of a freeware program. The Windows Essentials Codec Pack gives you the an easy way to play just about any audio or video type in Windows Media Player.

The Windows Essentials Codec Pack supports:

GP, 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, UMX and many more

After installing it, just try to open the file in question via Windows Media Player and it should work. If it isn’t already the default player for that type of file, just dragging and dropping the media file into there should work too.