You don't "run" or "open" this file directly. Windows calls on it automatically when you plug in an Apple device. You typically see an error related to usbaapl64.inf for one of three reasons:
The usbaapl64.inf file is a critical driver file used by Windows to recognize Apple devices like the iPhone, iPad, or iPod. You do not typically need to download this file from a third-party site; it is included with the official installation. Where to Find the File on Your PC usbaapl64.inf file download