System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("en-US");
or
System.Threading.Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo("en-US");
or
Application.CurrentCulture = new System.Globalization.CultureInfo("en-US");
or use language code instead of "en-US" string