How to backup photos from iphone 4s to windows 8 PC?

I have 600 pictures on an iphone 4s. I can browse them on the iphone. I connect the iphone to my Windows 8 laptop, and I can see the iPhone under My Computer. If I open it, I have a DCIM folder which says it's empty.

Windows 8 has a function to download from a phone if I tap the icon. It says there are no pictures on the iphone.

I can see them on the phone.

I want to back them up to my PC.

How?

ITunes.

Quote
Windows 8 has a function to download from a phone
Answer
you need a windows phone

You will soon start to find out other problems with your new windows 8 PC soon enough.