Q: How do I download iphone photos to windows computer

You can do it via USB cable as described in Import photos and videos from your iPhone, iPad, or iPod touch to your Mac or Windows PC - Apple Support

Other methods include 3rd party cloud services such as Dropbox, 3rd party apps such as http://www.photosync-app.com/, or Photo Stream (but only for new photos taken after Photo Stream is turned on) My Photo Stream FAQ - Apple Support