Microsoft has today made their RAW Image Thumbnailer and Viewer PowerToy available for download.
This utility provides for viewing of Canon (CRW & CR2) RAW and Nikon (NEF) RAW files
as well as TIFF images and other standard image formats (BMP, GIF, PNG, JPEG etc.).
The utility is split into a Windows XP shell extension which provides preview / edit
/ print commands for RAW files as well as a RAW viewer application.
The application is available for downloading here
. (47 MB)