Intruding here.

And a wild guess perhaps.

Is this something as simple as a setting in the Control Panel > Region and Language, then formats tab (and if necessary "Additional Settings")?

I realise that the Persian Language will be very different to English, but if this is an English computer with global settings for this language, perhaps you have to change something there, or even go to the "Keyboard and Languages" tab and install the appropriate language for what you want.

Mark