Is there a way to detect the Language of the OS from within a c# class?
With the System.Globalization.CultureInfo class you can determine what you want.
System.Globalization.CultureInfo
With CultureInfo.CurrentCulture you get the system set culture, with CultureInfo.CurrentUICulture you get the user set culture.
CultureInfo.CurrentCulture
CultureInfo.CurrentUICulture