Smart & Connected Life Travel Tech Troubleshooting SD Memory Cards by Kyle Schurman Freelance Contributor Kyle Schurman is a writer who specializes in digital cameras. His writing has appeared in Steve's Darkroom, Gadget Review, and others. our editorial process LinkedIn Kyle Schurman Updated on July 21, 2019 Brian Balster/Getty Images Travel Tech Digital Cameras & Photography Tips for Mobile Photography Tweet Share Email Although more and more digital cameras include internal memory, nearly all photographers invest in memory cards to store their photos. Memory cards, which typically are a little larger than a postage stamp, can store hundreds or thousands of photos. Consequently, any problem with the memory card can be a disaster — no one wants to lose all of their photos. Use these tips to troubleshoot your SD and SDHC memory card problems. Computer Won’t Read the Card Make sure that your computer supports the size and type of memory card you’re using. For example, some older computers can only read SD cards that are less than 2 GB in size. However, many SDHC cards are 4 GB or larger in size. You might be able to upgrade your computer to SDHC compliance with a firmware upgrade; check with your computer’s manufacturer. 'Card Is Write Protected' Error Message SD and SDHC cards contain “lock” switches on the left side of the card (as viewed from the front). If the switch is in the lower/bottom position, the card is locked and write protected, meaning no new data can be written to the card. Slide the switch upward to “unlock” the card. One Memory Cards Runs Slower Than Others Each memory card has a speed rating and a class rating. The speed rating refers to the maximum transfer speed for data, while the class rating refers to the minimum transfer speed. Check your cards and their ratings, and you’ll probably find they have different speed ratings or class ratings. Most of the time for general photography, a slower, older memory card will not cause any problems. If you're shooting HD video or using a continuous-shot mode, however, a slower memory card may be unable to record the data quickly enough, causing a video to be cut off or photos to be lost. Try to use a fast memory card for HD video. Recover Deleted or Missing Files If the memory card is operating OK, but you’re unable to find or open certain photo files, you can use commercial software to try to recover the photos, or you can take the SD memory card to a computer or camera repair center, which may be able to recover the photos. If your computer or camera cannot read the card, a repair center is your only option. Memory Card Reader Problems If you've inserted your SD memory card in a computer reader, you need to take some care to ensure you don't make a mistake that could cost you your photos. When you delete any photos from the SD memory card through your computer's memory card reader, for example, the photos are permanently deleted; they do not go to the computer's Recycle Bin. So take a lot of care before you delete any photos from the SD memory card using your computer's memory card reader. Formatting SD Memory Cards Deciding whether to format requires a little thought. If you know the card contains photos, you will not want to format it, because formatting erases all data from the memory card. If you receive this message on a memory card you’ve used previously and on which you’ve stored photos, the card or camera could be malfunctioning. It’s also possible that the SD memory card may have been formatted in a different camera, and your camera cannot read it. Otherwise, if the memory card is new and contains no photos, it is OK to format the memory card with no worries. The Computer Won't Read the Card As you move your memory card from a slot in a computer to a printer to the camera and anywhere else you're using the memory card, you can potentially damage or introduce grime to the metal contacts on the card. Make sure the contacts aren't covered by grime and don't have any scratches on them, which could cause the SD memory card to be unreadable.