You may be able recover:
• Photographs on the memory card that have been deleted.
• Photographs on a corrupted memory card.
Recovery is often successful because usually only the memory card's FAT (File Allocation Table) has been deleted or corrupted.
The FAT is like the table of contents of the card.
When a file is deleted or corrupted, usually only the entry of the file in the FAT is deleted or corrupted.
Deleted photographs may still be present if they haven't been overwritten by more recent photographs.
Do the following:
1) Don't use the card.
You don't want to write over the files that are already on the memory card.
2) Go to the website of the card manufacturer and look for a file recovery program.
3) Search online for recovery programs if the card manufacturer doesn't provide a program.