How do I get locale information about logged-in user from an administrator process on Windows XP in c++?

Question

A similar question got asked by others here at least twice already (see links below) but never properly answered, perhaps because it wasn't put the right way. Let me have a go:

I have a process running under the local account on Windows and I need locale information about the user who is logged into the interactive session if there is one or any interactive session if there is more than one.

I need to know the user's language and country settings and it has to work on all kinds of Windows starting XP Service Pack 3.

I very much appreciate your answers!

The previous related questions that didn't really get answered:

• C# window xp current user when using run as
• https://stackoverflow.com/questions/5778378/creating-a-process-as-logged-on-user

Answer 1

I would do it in the following way:

1. Enumerate logon sessions using LsaEnumerateLogonSessions
2. Call LsaGetLogonSessionData to get logged on user SID identifier.
3. Call ConvertSidToStringSid function to get a string representation of a sid.
4. Look up registry setting HKEY_USERS[USER_SID_STRING]\\Control Panel\\International

This key has all sorts of information needed, and looks like all listed WINAPI finctions are available starting at Windows XP.

So this should work.