An excerpt from a previous post:
I've installed the UK English pack so now my system supports both UK/US english.
I've set the default language for the system to UK, and the users are set to UK.
However, if I go into any TUI bit to record a greeting I'm always prompted whether I wish to record for US or UK English - is it possible to disable US English so that this question isn't asked?
Answer from Jeff Lindborg:
No, for each active language on the system (you can take US english out of the active list if you like) subscribers are given the option to record greetings for any of the languages - there's no way to have a list of languages that are installed and active for the TUI that are not offered for greeting recordings for subscribers.
So how do I remove a language from the active list?