This is a sure incident which occurs in everyone's life at least once. Don't freak out! Whenever you delete a file on your computer, it does not get completely deleted from the hard drive, unless something is overwritten on those sectors. Hard drive is designed in such a way that it enhances the disc life by utilizing the drive's sectors in most efficient way.
When you realize that you have deleted file/s permanently from your computer, Recuva gives you another chance to get them back. You can also get deleted files from your recycle bin. Recuva will help you get those files back from computer HDD, memory card and other portable media. Recuva is probably the best software currently available for free.
Get Recuva here
Run it as administrator by right clicking.
After successful installation, launch Recuva and select the file type you want to recover.
e.g. media, video, pictures, music, document, emails etc.
Select the possible locations for your missing files, It could be easy for one to recall where they had kept those files.
Your portable devices must be connected before your proceed to search in those locations such as ipod, usb flash drive etc.
Click Start button to initiate the recovery and Recuva will take its own time to list the files which were possible to locate on the drive. It is not 100% method to get all files back but mostly works well for recent missing files. Files deleted long time back or overwritten with other files are impossible to recover with any such software.