Like a bad vending machine that takes your money without coughing up the product, a damaged memory card can seemingly eat your data. In some cases, you may be able to stick your hand down the card's proverbial throat and get it to cough up data that you have saved on it. The first thing to do is test the memory card using a USB memory card reader and your computer to see if it will recognize the card. If your computer system doesn't recognize the damaged memory card, use the Windows "chkdsk" program to repair it.
Insert your memory card into a USB memory card reader. Plug the data cable for the USB adapter into a USB port on your computer. Windows automatically recognizes the device and assigns a drive letter to it. Double-click on the drive letter that Windows assigned to the device. If you can access your data, the card is working.
Click the Windows orb on your taskbar, if nothing happens or you receive an error message when you double-click the card's drive letter. Type “run” (without the quotes here and in subsequent commands) in the “Search programs and files” text box. Click the "OK" button to open the Run pop-up box. Type “cmd" in the text box and click on the "OK" button to bring up a command prompt box. Type the "chkdsk" command and specify the drive letter to check, followed by "/r." The resulting command will look like this example: chkdsk e: /r. Press "Enter" to execute the command and check the memory card for errors.
Wait until the "chkdsk" program finishes checking your memory card for structure corruption. Press the letter “Y” on your keyboard to allow the program to continue checking, until you recognize the files and directories that you have saved on the memory card. When "chkdsk" is finished checking the memory card, you're prompted to save lost chains into files. Click the “Yes” option. In a few moments, "chkdsk" will display all of your lost data files that have been repaired on your computer.
Switch to the desktop and double-click on “Computer,” and then click on the drive letter that Windows assigned to the memory card. All of the files that were repaired will be visible, and you'll be able to access them again on the memory card.
Remove the memory card from the memory card adapter. Unplug the data cable to the memory card adapter from the USB port on your computer. Insert the memory card into the mobile device that you normally use to access the files on it.