From Ardfry Imaging:
View Adobe Digital Negative files throughout Windows 7, Windows Vista, and Windows XP SP3. The 64 bit DNG codec by Ardfry Imaging is a plugin for Windows that allows you to use Explorer and Photo Gallery, the RAW Viewer in Vista, to view thumbnails, metadata, and previews of DNG files. You can also view your DNG files in Windows 7 Media Center. Easily manage digital assets from Windows Explorer without having to launch another application. You can take advantage of the advanced search capabilities of Vista to search for DNG files based on metadata.