Welcome to Android Central! When you connect the phone to your PC via USB, swipe down the phone's notification panel and tap the USB notification. Make sure MTP is selected. Then open Windows Explorer and look for the S5 in the device list. You should be able to find your photos and videos in the /DCIM/Camera directory. (Don't use the Windows Import All Photos and Videos feature -- it will indiscriminately import all images, including cached images saved by your apps and browser.)