When I build my WPF Project, it creates several language folders, each containing \"Microsoft.Expression.Interactions.resources.dll\".
The weird thing is that I never cr
You're seeing those files because you're using the Blend SDK for .NET (either directly or through the Prism library). That SDK includes localized resources thus they get included in your build output.
Here's how you create a Silverlight build that targets a specific culture. It should work the same way for WPF. The jist of it is:
If your solution is quite large this could be a lot of work. Honestly it doesn't harm anything to have this additional files in a WPF application -- they simply take up a little more disk space. You could also only archive and ship the en culture resources. Assuming you've defined your NeutralResourcesLanguage as en your the application will always be able to find its resources (they'll just be in English).