Microsoft recently added a new utility to the Windows XP PowerToys collection, its called the 'RAW Image Thumbnailer and Viewer' . This utility adds new functionality to the Windows Explorer, it allows you to see thumbnails, view the file's meta data, preview, and print photographs stored using the RAW image file format. This is a digital image format that is primarily used by most Canon and Nikon digital cameras.
Digital photographs stored in the RAW image format are stored uncompressed, meaning that no image quality is lost due to compression (such as JPEG image files). Since these files are uncompressed, they will also be several times larger then the same version of the files that is compressed.