Can't get photos from SDHC card

Marg399

Honorable
Dec 11, 2013
1
0
10,510
I have a Canon SX40 and have had no problems until now. While on holiday the SDHC card ran out of memory and I inserted another. On my return I connected the camera to my computer, Camera Window opened and I transferred all my photos from the second card. However, when I put in the first card I got the message that the camera was not detected. The camera does not show up in MY Computer either. I tried inserting the card directly into the reader on my computer but it doesn't show up. How can I get the photos from this card? I can look at them all on the camera and get no error messages. Any help greatly appreciated!