From personal experience I know that iTunes can be a b-word to get all these things sorted because it doesn't allow to freely do as please but here's the solution: https://itunes.apple.com/gb/app/simple-photo-video-transfer/id420821506?mt=8 Simply install it on your iPhone and while keeping it running, go to the browser on your PC then click on the box to transfer the file you want, afterwards it'll send to the iPhone and it's done.