Click the Customization button (next to the Play button) → Manage installation → Configure .
This is a common misconception. Prince of Persia (2008) was never recorded in Persian/Farsi. The "original" voice track is English, performed by Nolan North (the Prince) and Kate Higgins (Elika). There are no official dubs for Middle Eastern languages. The only official dubs are English, French, German, Italian, and Spanish. prince of persia 2008 language change