Does Microsoft have a best practices document regarding the storage of App Data vs User Data on different Windows Platforms?

Question

When creating an application that will be targeted to many versions of Windows what is the best practice to determine where application specific data should be stored. Speci

Answer 1

There's a good description here of the various CSIDL values and the folders they refer to (including a description which should hopefully tell you what you need to know).

It also contains links to the functions you should use to retrieve these special folder paths.

Note that, as of Vista, the method has changed a little. It now uses KNOWNFOLDERID instead of CSIDL and the functions have changed as well. See here.

You can still use the older functions (at the moment) since I believe they're now just wrappers around the new ones. At some point in the future, that may change.