[Guy Harris <guy@xxxxxxxxxxxx>]

On Feb 3, 2004, at 1:23 PM, Olivier Biot wrote:

> I'm not saying that it is a MUST requirement; however I see on my PC
> running WinXP Home that Adobe Reader, Quicktime, Symantec, MSN
> Messenger 6 are applications with configuration data in the "Documents
> and Settings/All Users/Application Data" directory. I see this more as
> a cosmetic thing to "fix", but I do not know the *exact* rules
> stipulated by Microsoft (except from the "put all in registry").

Well, according to

	http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ 
dnw2kcli/html/w2kcli_chapter4.asp

in "Application Specification for Microsoft Windows 2000 for Desktop  
Applications":

	Using Application Data Folders

	The CSIDL values described here provide a consistent, unified way to  
access the physical paths to the desired folder locations, independent  
of the operating system. The preferred API is SHGetFolderPath, because  
it behaves consistently across all versions of Windows. To access the  
path for application data, applications should call SHGetFolderPath  
with the appropriate CSIDL and then append [company name]\[product  
name]\[version] to the returned path.

	Specifically, to retrieve the CSIDL _APPDATA path:

		TCHAR szAppData[MAX_PATH];
			…

	hr = SHGetFolderPath(NULL, CSIDL_APPDATA, NULL, 0, szAppData);


	When storing application data in the user profile, applications should  
use the same hierarchy under Application Data and Templates as is used  
in the registry:
	   [User Profile]\
	      Application Data\
	         [company name]\
	            [product name]\
 	              [version]\
	                  [file or folder]


	Data Type                Folder CSIDL           Folder Location

	Per user, roaming        CSIDL_APPDATA          [user  
profile]\Application data
	Per user, non-roaming    CSIDL_LOCAL_APPDATA    [user profile]\Local  
Settings\Application data
	Per machine (non-user
	specific & non- roaming) CSIDL_COMMON_APPDATA   All Users\Application  
data

	o CSIDL_APPDATA

	As part of the User profile, this folder will roam. Use this folder to  
store all user-specific application preferences. For example, if a user  
can specify a custom dictionary to be used in your application, you  
should store it here. That way if the user roams from computer to  
computer, their dictionary will roam with them. This also allows other  
users to have their own individual custom dictionaries.

	o CSIDL_LOCAL_APPDATA

	This folder is for application data that does not roam. It is still  
part of the User profile, so this is still per-user information.  
Application data that is machine-dependent, such as user specified  
monitor resolution, should be stored here. This data must not roam  
because different machines have different monitors. In addition, large  
blocks of data which can easily be re-created should be placed here to  
minimize download time that is incurred when roaming. For example,  
Internet Explorer keeps its cache of downloaded html/gif pages here so  
that they don't roam with the user. But the smaller cookie and history  
lists are stored in CSIDL_APPDATA so that they roam.

	o CSIDL_COMMON_APPDATA

	This folder should be used for application data that is not user  
specific. For example, an application may store a spell check  
dictionary, a database of clip-art or a log file in the  
CSIDL_COMMON_APPDATA folder. This information will not roam and is  
available to anyone using the computer. By default, this location is  
read-only for normal (non-admin, non-power) Users. If an application  
requires normal Users to have write access to an application specific  
subdirectory of CSIDL_COMMON_APPDATA, then the application must  
explicitly modify the security on that sub-directory during application  
setup. The modified security must be documented in the Vendor  
Questionnaire.

which suggests that not only should global settings files go in  
CSIDL_COMMON_APPDATA, so should all the *other* non-executable files we  
now install in the installation directory!

However, this page:

	http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ 
shellcc/platform/shell/reference/enums/csidl.asp

says of CSIDL_COMMON_APPDATA that known only to version 5.0 of the  
Shlwapi.dll:

	http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ 
shellcc/platform/shell/programmersguide/versions.asp

so if we used the appropriate Shell API's to get it, we'd somehow have  
to deal with systems with older versions of those APIs.