Plug the S4 into the desktop. Look in Windows explorer (if a window doesn't pop up asking what you want to do with the phone - if it does, tell it to open a window). It may take a minute.
Then click on the phone (if you opened the window manually the phone will be in This Computer). You should see a folder named Phone. Open that. Find the DCIM folder and open it. Open the Camera folder. Your pictures should be in there. Just drag them to a folder on the computer and drop them. (If there are a lot of them, don't do all of them at once - USB ports sometimes overheat and shut down with huge file transfers. Do a few at a time.)