Who needs language packs? After I visited Hamburg, I though all Germans speak very good English. I has this illusion until I visited Berlin.
Well, I would suggest to do just the opposite: avoid dependency between target machine settings (did you mean dependency of international settings?) and installation of a version of localization. Yes, the creator of the application should only provide a set of localization, but who will decide which culture to use? The settings for application's localization should be chosen by the user and only by the user. Also, the user should be able to switch to a different culture at any moment, which is technically very easy with .NET.
Here is why: even if you achieve what you are asking about, it cannot be reliable. There is nothing with tracks relationships between application culture and system settings. I mean, anyone can change the system settings anytime, but it won't affect application settings. Another reason is this: to me, the best installation is no installation: the application should be fully functional if the content of the output directory is simply copies as it on the target machine. These days, Microsoft started to strongly encourage such approach, which seems to be really important to me. That said, the long-term application settings should be set up by the application itself. One of such settings should be the UI culture.
You should understand one thing. If you're using German, you're using something which is really close to English, which is just yet another Germanic language. German UI might be an adequate language to use in UI. Try to think Russian or, say, Hungarian. Being a fan (and, to a certain extent, an expert) of Russian language, I avoid using it in UI — it just does not seem to play well even though it looks perfect in Russian Web sites and elsewhere. I simply cannot tolerate the ugly usage of my language most programmers do and highly prefer English. Perhaps you would be surprised to know how many people of different cultures prefer English in UI. This should be a choice of a user which should be possible to make at any given moment of time.