An application is required in order to transfer photos from the iPhone 5 mobile phone to your PC. In this case, iTunes is the official way to transfer photos from your iPhone to PC. Download iTunes from its official website and install it then connect your phone.
The most easiest way is to follow the Apple page for this operation. It's explained exactly for every OS.
Note: Although iTunes is not mentioned on the page, it is, however, required to install the necessary drivers for the phone.