I'm working with a very old installer that can read Registry entries but has a difficulty (complex) time executing Windows APIs.
I'm trying to detect whether the PC it's being installed on is in Australia.
sets the default language for the login screen
The different country codes are listed here:
From my testing and the MSDN page below, this will work:
This corresponds to setting in the Region Options ("Select an item to match it' preferences".
This has the advantage of also being able to be read from a non-admin account.