Windows 7 has seen an improvement in the media side as it adds support for H.264, Xvid, and DivX. This support was added by Microsoft so that most of the media files downloaded from the internet could be easily played using Windows Media Player without the user having the need to install additional codecs or another media player. Although this addition seems to cover support for the most downloaded media from internet, there are still many more formats which are not natively supported by Windows 7. You may choose to install a new media player like VLC Media Player or Media Player Classic to give you support for even more media formats or install a codec package so that you wil never have to worry if Windows Media Player will be able to play the file or not.
Although popular codec packages like K-Lite still appear to work in Windows 7, you would want to install a codec package that was intended for Windows 7 so that you do not encounter any problems later on. The release of Windows 7 Codecs Package, from the author of Windows Vista Codec Package, gives you the peace of mind to install Windows 7 codecs without having to worry about compatibility issues. You can download Windows 7 Codecs from here.
The Windows 7 Codecs Package will not install any media player or change associations for any file types whatsoever. The installer will automatically remove any existing popular codec package to avoid any problems. You can remove the codecs package or part of the codecs package at anytime you want. Have fun with Windows 7!Google+