[This is preliminary documentation and subject to change.]
Recommendation (Designed for Microsoft® Windows® Logo)
By default, user data should be stored in the user profile. On Microsoft Windows NT®, this means that applications should use the following folders to store user document files and large user profile data, respectively:
%SystemRoot%\Profiles\username\Personal
%SystemRoot%\Profiles\username\Application Data
Paths to these folders should be obtained by calling SHGetSpecialFolderLocation with the CSIDL_PERSONAL and CSIDL_APPDATA constants, respectively.
On Microsoft Windows 95 and Windows 98, applications should explicitly create equivalent folders to use for this purpose:
...\windows\Profiles\username\Personal
...\windows\Profiles\username\Application Data
Application Data\
Software\
[company name]\
[product name]\
[version]\
[your top level]\