Import Pictures and Videos keeps importing existing photos

I use the Import Pictures and Videos function to load copies of my photos from my Panasonic camera to my desktop pc. I do this about once a month. Today it started to copy all the old photos that have been already transfered. They are being put in the same folders as the original, a suffix (2) is added to the file name. I have reviewed the settings in Import Pictures and Videos and can't see any problem. The folders are named with the date they were taken, and I don't use any tags, so they look like this:

D:\Photos\Panasonic\2016-07-31\P1000049.JPG
D:\Photos\Panasonic\2016-07-31\P1000049 (2).JPG

I noticed that just one of the duplicates had a date/time that was exactly 1 hour different. This led me to suspect that the change from BST to GMT that we have in the UK may be to blame (although as I said it was only one affected). I realised I had not altered the time on the camera. So I did this and repeated the transfer. It made no difference.

If anyone has come across this and has a solution I would be grateful to hear it

When you connect your camera to your computer with a USB cable, the camera will likely become a "flash drive" in Windows. Therefore, to transfer pictures, the only thing you need to do is open File Explorer, browse down to the picture folder(s) in the camera, and then either copy or move the pictures from that folder (those folders) to your computer's hard drive.

Transferring the pictures and videos in this way will ensure that you are transferring exactly what you want to transfer.

Also, if you "move" (rather than "copy") the pictures and videos from the camera to your hard drive, you will never again get duplicates, because when you "move" them, you are removing them from the camera.

Thanks Jim, you are quite right. When I connect the camera I can see the camera memory card as if it were a usb stick, and can transfer the photos that way. I particularily liked the automatic Microsoft transfer as it would create directories (date photo taken), which is easier than creating them myself. But it looks as if this is what I'll have to do.

Incidentally, you mentioned that if I move them they will be deleted from the camera. Whenever I try this, or indeed try to delete from the memory card - either when connected via the camera or placed in a card reader, I am unable to do this. I suspect there may be some software erase protection in place. I'm OK at the moment as I have plenty of room on the card. But this won't last.

I suggest that you move everything off of the camera and onto the computer's hard drive. Then format the camera's storage area, which will wipe it clean. Then, if you want any pictures on the camera, you can copy them from the computer to the camera.

Sometimes the only way to erase the things on a storage device is to format the device.