Nikon D3100 Memory Card

When I have my memory card inserted into my Nikon D3100 it shows that I only have two photos. However when I insert the card into my photo printer it shows all of the photos on the card! What did I do wrong? Why aren't all these photos showing up on the camera itself?

ONLY the photos you took with your camera that were saved to your memory card will show up on the camera]

What you should be doing is this

* At the end of each shooting day, copy all the image files to your computer.
* Once they are safely on your computer, format the card using the format feature on your camera

NOTE: Neither your camera is a device to show off your photos, nor is your memory card a permanent storage location

In my camera, if you changed the files, they sometimes won't load a thumbnail. Like if you rotated the image or adjusted the image in photoshop and saved it back to the card.

Did you format your brand new memory card (via your camera Menu) before you used it the very first time? Have you reformatted it regularly thereafter to delete all files from it? So… After your day's shoot, do you transfer All files to your computer, backup your files, then reformat the card? If not, that's what you really should be doing to keep your memory card in good working order. They are not meant to be used for permanent storage, only temporary.

So, I recommend you transfer All files from the card as soon as you can. Use a card reader to transfer, not your camera (your computer may have one built-in or you can use/buy an external USB card reader). When all your files have been transferred, back them up… Then reformat your card.

Also, as already mentioned… Your camera will only be able to recognize images that were taken by it and the files have not been changed in any way.So, if you have transferred files with a different file name back onto the card, then don't expect your camera to recognize them. You shouldn't be doing that, anyway. There's no need for it.