I'm currently trying to get my head around MUI, and getting some issues with GetSystemDefaultUILanguage - it's not returning the language I'd expect:
Users can set the language used for Windows startup messages in the "Welcome screen and new user accounts settings" dialog - which claims to copy language settings to system accounts. I'd expect therefore to be able to get the language used by startup messages using GetSystemDefaultUILanguage - but it seems to only ever come back with the language used to originally install the OS. How can I get the startup messages language?