برای فارسی کردن
System.Windows.Forms.InputLanguage.CurrentInputLanguage = System.Windows.Forms.InputLanguage.FromCulture(new System.Globalization.CultureInfo(1065));
//Or یا
System.Windows.Forms.InputLanguage.CurrentInputLanguage = System.Windows.Forms.InputLanguage.FromCulture(new System.Globalization.CultureInfo("fa-IR"));
برای انگلیسی کردن
System.Windows.Forms.InputLanguage.CurrentInputLanguage = System.Windows.Forms.InputLanguage.FromCulture(new System.Globalization.CultureInfo(1033));
//Or یا
System.Windows.Forms.InputLanguage.CurrentInputLanguage = System.Windows.Forms.InputLanguage.FromCulture(new System.Globalization.CultureInfo("en-US"));