Some photos on my SD card will not open. How can I recover them? I don't think they are lost, because I can see them but I can

Well it depends on what device the SD card was in when the photos were put on it. You didn't list a device.

You should actually place the SD card back in that device, and then, if it is a tablet or phone, connect it to a computer via USB cord and try viewing them that way.

If you are trying to access them by placing the SD card into a computer, you should try moving them off the SD card onto the computer (in a folder) and then see if you can open and view them from there.
 


I took them with a Nikon D7200, I moved them from the SD to the computer but still can't view them. I will try with a USB cord and let you know. Thank you

 
Are you sure then that they are compatible images to whatever program you are trying to view them through? Some cameras save images in formats that not all programs open.
 

Yes because now when I go look at them on the camera they have a red box with a red square. All the others look fine on the camera and in the computer.