Codec Pack for Windows 7
Windows Media Player 12, in Windows 7, now supports DivX, XviD and MP4 video files, but in case you still have problems playing any file, you can try this codecs pack, specially for Windows 7.
Win7Codecs is a comprehensive package of codecs for Windows 7. It is like a plug and play package that will play all media files on WMP, right after installation!
The installer removes any previous codecs installed, and installs the new ones from this package. You don’t even have to make any configurations, tweaking, adjustments in your media players, and you can play your media files after installation.
Users of Win7Codecs 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.
You can download Win7Codecs and enjoy all your videos on Windows 7.