uninstall whatever codecs you have already installed such as haali, cccp and klite and use the Win7codecs
To complete the install you must open the Settings Application using a rightclick on the shortcut
and choose Run as Administrator.
These codecs are designed for Windows 7 and will display all file properties in explorer.
Another useful setting is the [x] SUGGESTED settings checkbox;
which will setup the Windows players as the default players for all media content.