I'll sneak in before Griff manages to do his thing, you should take a look at Where Should I Store My Data?
] which gives examples of why storing data in the application directory might not be a good idea. If the application is installed in a protected place, such as Program Files or even the base C:\ directory, you could have problems opening and writing files to those locations.
Instead consider using some of the directories the system has specifically for storing data for either all users or the local user. These would be places indicated by the