Cannot transfer pictures from camera roll to computer
I want to back up my pictures from my iphone. When I plug in my iphone 6s plus to the computer to transfer pictures, I can only see some pictures but not everything in my iphone. I can only view 2,000 of 6,000 pictures, and only the latest pictures. there's about 50 folders, but most of them are empty or only have 1 picture in every folder. Help! I didn't have this problem before. Someone said my unlock the phone. How do you unlock the phone.
iPhone 6s Plus, Windows 7