In Windows Vista you can add information to music and photo files such as titles, ratings, comments, and more. Although, if you don't want to share this personal data if you share these files with other people you can remove it.
Right-click a file, choose Properties, then click the Details tab. At the bottom of the window there is a link called 'Remove Properties and Personal Information.' From there you can remove the information from the file, or create a copy of the file with that data removed.