What's wrong with this code?

Error(Exception) message :

> 
> Not a valid calendar for the given culture.
> 
> 
> 

```
System.Globalization.CultureInfo ci = new System.Globalization.CultureInfo("fa-Ir"); //Error
ci.DateTimeFormat.Calendar = new System.Globalization.PersianCalendar();
Application.CurrentCulture = ci;

```

And what's its solution?  

Can I add a `Calendar` type to Windows XP regional option?