Microsoft wants to make it easy to label photos with metadata--information such as where the picture was taken and who's in it--but you should be careful before you use the company's software for doing so.
According to one Microsoft Knowledge Base article, "When you edit the properties of a photo to add metadata to that photo in Windows Vista, the software for the digital camera may no longer recognize the metadata that is automatically added to the photo by the digital camera."
Another alert regards using Photo Info to change metadata on NEF images--the "raw" photos directly from the cameras' image sensors. "Microsoft has received reports of compatibility issues with Nikon NEF files after installing version 1.0 of Nikon's raw codec posted in January. Tagging the raw files through Windows Vista or the Microsoft Photo Info tool after the codec is installed appears to cause these files to become unreadable in other applications, such as Adobe Photoshop," Microsoft said in a a frequently asked-questions list for the Photo Info software.
Microsoft, Windows Vista, Meta Data