Can't transfer photos from my android phone to computer

[AC Question]

I have a Samsung Galaxy 4-G android phone. I have to transfer photos to my computer. I have connected the USB cable and found the location on the phone where the photos seem to be--DCIM, Camera. But the icons are not showing the individual photos, just the little flower picture for a general photo. I have tried to drag and drop them into the computer folder I want them to be in but they are not transferring. I also tried to copy and paste but no luck. When I tried to open a photo by clicking on it, I got a message that it could not be opened because the files are corrupted or damaged.. I have never had this problem before in trying to transfer photos. Can anyone help me? P. S. I tried other photos that in the past have copied properly and they will not open either.