D5100 memory card folder structure
I always use a card reader, so I don't know the answer to your question about viewing the folder structure when connecting the camera to the computer. Is there a "sort by date" feature you can use?
The first thing you need to do is set your File Number Sequence to On in the Custom Settings menu. This will prevent the duplicate file names, at least from now on.
When I downloaded photos from my D5100 to a computer, I noticed that a lot of files have duplicate names (two DSC_0008 files, two DSC_0024, etc.). I realized these files came from different camera folders: 100D5100 and 101D5100. The problem is that I can't see the internal folders under My Computer/Scanners and Cameras/D5100. Is there a way to see the internal folders on a memory card when the camera is connected to a computer? This would make sorting through the files a lot easier. Unfortunately, I do not own a card reader so I can't go that route. Thanks in advance!