Codecs have been a problem for most users at one time or another.
This is because there has never been an 'out of the box' working solution that the average computer user could install and just have everything work properly from the beginning.
There are several decent codec package solutions out there, but none of them did everything I wanted.
I was always in need of a tweak, adjustment, or even a re-installation just to get the codecs I needed/wanted and most of the time, the file still didn't play properly.
I've never claimed to be a media guru.
My media experience prior to creating these packages was to doubleclick a file I downloaded and hope that it played.
So with the help of the MSFN community, I decided to package up the bare minimum of codecs required by most computer users and share them with the rest of the world.

The installer will automatically remove most other popular codec releases from your computer before installing this concise yet comprehensive package.
You won't need to make any adjustments or tweaks to enjoy your media content immediately.
Windows Media Player and Vista's Media Center will instantly recognize all your files as playable.

It does not contain a media player and it does not associate filetypes.
With this package installed you will be able to use any media player, limited only by the players' capabilities, to play all movies and video clips.
Streaming video is supported in several formats in all popular web browsers. Users of VCP have the ability to choose what is installed and where to install it using the public redistributable.
After installation you can select to remove specific portions without removing the entire package.

You can also re-add the removed items at any time.  
I recommend that you UNINSTALL YOUR OLD VERSION but this is not required.

If Windows fails to playback DVD's install Media Player Classic to play DVD's.
You may also choose to install the Cyberlink mpeg2 codec separately but this is not recommended on Vista Ultimate/Premium.

Included:

Media Player Classic v6.4.9.1 rev 55
2.01 MB
Last Updated June 13th, 2008 (for general use)
MPC HomeCinema x86 and x64 versions are available, with or without an installer.
(updated constantly)
When using the HomeCinema version from above, take notice that most of the internal codecs are being used.

Cyberlink mpeg2 codec

Extra:
TweakUAC (execute and use)
84.3 KB
Last Updated June 22nd, 2007
With this tool that you can quickly turn User Account Control (UAC) of Windows Vista on and off.

Changes in version 4.7.1 on July 12, 2008:
- update ffdshow to rev. 2035
- update 10 of Gabest decoders
- add shortcuts for DVR-MS settings
- add several filetype recognitions to WMP11