NTW & Steam

If i buy a boxed version of NTW, will it work with my Downloaded Empire Version from Steam?
Or is Napolean Stand Alone and Installes into a Completely different Folder on Steam?

Napoleon is a stand alone game, so it doesn't matter which version of empire you bought. i also bought the boxed version of napoleon, you have to verify it through steam though.

It's stand alone. And even if it was an expansion, since Empire: Total War all TW games use Steam as registration software.

And yes, it does install into a different folder.