The Windows 7 Codec Pack supports almost every compression and file type used by modern video and audio files.
The package is easy to install, while also offering advanced settings to the high end user:
For simple installation select "Easy Installation".
For advanced installation options select "Expert Installation".

Codec's Explained:
A codec is a piece of software on either a device or computer capable of encoding and/or decoding video and/or audio data from files, streams and broadcasts. The word Codec is a portmanteau of 'compressor-decompressor'

Compression types that you will be able to decode include:
Hi10p/10bit x264 | x264| h.264 | AVC | DivX | XviD | MP4 | MPEG4 | MPEG2 and many more.

File types you will be able to play include:
.mkv | .bdmv | .evo | .avi | .flv | .mp4 | .ts | .webm | .m4v | .m4a | .ogm | .ac3 | .dts
.flac | .ape | .aac | .ogg | .ofr | .mpc | .3gp and many more.

Resolutions supported include:
All resolutions upto, and including SD (Standard Definition) 480i, 480p, 576i, 576p, + HD (High Definition) 720i, 720p, 1080i, 1080p and beyond.

By using SlySoft AnyDVD HD with this Codec Pack users can play:
Protected Bluray, HD-DVD, AVCHD, DVD, CD discs.

Package Components:
- ffdshow DirectShow Video Codec 20120205 x86 Revision 4305 by clsid.
- ffdshow DirectShow Video Codec 20120205 x64 Revision 4305 by clsid.
- LAV Video decoder 0.45 x86 & x64.
- XviD Video (Encoder) Codec v1.3.2.
- Lagarith Video (Encoder) Codec v1.3.27 x86 & x64.
- Flash Video Splitter/Decoder v1.5.2.3456 x86 & x64.
- AC3Filter v1.63b AC3/DTS Decoder x86 & x64.
- LAV Audio Decoder 0.45 x86 & x64.
- DivX Audio Decoder 4.1
- Lame MP3 v3.98.2 ACM Encoder/Decoder Codec.
- DSP-worx Bass Source Filter/Decoder v1.30.
- Haali Media Splitter/Decoder 16/09/11 x86 & x64 - For MP4, MKV, OGM and AVI files.
- LAV Splitter 0.45 x86 & x64.
- VSFilter v2.39.5 x86 & v2.37 x64 - Subtitle Readers.
- CDXA Reader v1.5.2.3456 - Also known as Form 2 Mode 2 CD or XCD x86 & x64.
- GSpot Codec Information Appliance v2.70a.