SD or Secure Digital cards are used to store and exchange information between digital cameras, cell phones, Personal Digital Assistants (PDAs), and even small computers. Occasionally, the cards crash or accidentally delete data by the user. If this happens to you, then you can use a free file recovery program to recover the deleted files.
Steps
Method 1 of 2: Using PhotoRec for Mac and Windows

Step 1. Go to the PhotoRec Wiki or click here

Step 2. Find the 'Latest Stable Version' box and click on '7.0'
This box is located in the top right corner of the page.

Step 3. Scroll down to 'TestDisk & PhotoRec 7.0' and click on the version that is compatible with your computer

Step 4. Download the zip file to your desktop

Step 5. Double click on the file to extract it

Step 6. Insert the SD card into your computer

Step 7. Click on 'testdisk7.0' to open it

Step 8. Double click on the 'Photorec' file to open the program
A terminal window will appear with the PhotoRec 7.0 program.
If a message appears, give permission to run the program

Step 9. Select your SD card or drive, and press ↵ Enter
Since your mouse doesn't work in the terminal, you have to use the arrow keys on your keyboard.
You may be presented with several options on this screen. Note the size of each disk displayed and choose the drive that is the same size as your SD card

Step 10. Select the partition type and press ↵ Enter
Mac users then choose 'P Fat16 >32'. In Windows, choose 'P Fat32'. Allows the program to scan the identified directory system.

Step 11. Select the file system '[Other]' and press ↵ Enter

Step 12. Select 'Free' to search for files in Fat16 or Fat32 format
Only choose 'Whole' if you think your SD card is damaged

Step 13. Use the arrow keys to choose a storage location for the recovered files
- You can now create a folder for the recovered files.
- Do not save the files to the SD card.

Step 14. Press C once the location is correct
The recovery procedure will start automatically.

Step 15. Wait for the recovery process to complete

Step 16. Navigate to the location you selected in step 13 to view the recovered files
Method 2 of 2: Using Recuva for Windows

Step 1. Go to the Recuva homepage or click here

Step 2. Select 'Download Free Version' followed by 'Free Download'

Step 3. Click on 'FreeHippo.com' or 'Piriform.com'
The website will open and the download will start automatically.

Step 4. Click the downloaded file at the bottom of the web page to open it

Step 5. Select 'Run'

Step 6. Install Recuva
To install this software on your computer, follow the steps below:
- Click on 'Ok'.
- Click on 'Next'.
- View the license agreement and select 'I Agree'.
- Click on 'Install'.
- Uncheck the box next to 'View Release notes' and click 'Finish. The program will start automatically.

Step 7. Insert the SD card into your computer
If prompted to format the SD card, check the box next to 'Quick format' and click 'Start'. This will clear the file table from the SD card and keep the data untouched.

Step 8. Return to Recuva and click 'Next' to continue after the welcome screen

Step 9. Select the type of file or files you want to recover and click 'Next'

Step 10. Select your SD card as the file location
Choose 'In a specific location' and click on 'Browse'. Scroll through the list and select 'Removable Disk'. Select the 'DCIM' folder if necessary. Click on 'Ok' followed by 'Next'.

Step 11. Click 'Start' to run the program
As the program recovers the files, they will appear on the screen.

Step 12. Check the box under each file you want to recover

Step 13. Click on 'Recover'

Step 14. Select a location to save the files and click 'Ok'
The files will be restored to the location you selected.

Step 15. Click 'Ok' when the recovery process is complete

Step 16. Navigate to the location you selected in step 14 to view the recovered files
Warnings
- An ignorantly removed SD card can damage data.
- Thoroughly check the PC where you are going to insert the SD card for viruses/malware or other suspicious programs.