Well this depends on a variety of things. If you noticed that a file you wanted was missing after months of using your computer/laptop and are unsure WHEN the file got deleted.. chances of recovery are slim.
When a file gets deleted there is a pretty good chance of being able to get it back. However, each time you save a file or save changes to files, installing and uninstalling programs that chance goes down. When you make changes like that you essentially are writing over the space that your file once occupied if that makes sense. Same with SD cards. If you took a bunch of photos and deleted them by accident (or your child went keyboard ninja and deleted them for you when you were transferring them to your hard drive) you still have a pretty good chance of recovering your files.
- Download and install Recuva from here (you only need the free version): Click Here
- When you open it, the program should open a wizard.
- Click next in the wizard, then click on pictures.
- Click on next again.
On the next screen choose the location you want to search for the files.
Click on next again and then it will look for the files.
SAVE the files found on an external drive, or flash drive. Unfortunately if it does not find anything it means the photos are gone. I have had edited photos deleted by my son and I was unable to recover them but Recuva recovered the UNEDITED photos for me. So it all boils down to how soon you noticed the problem.
IF that doesn't work and you want to take things a step further try this program recommended here:
https://code.google.com/p/sdcardrecovery2013/




