It must have happened to you that you accidentally deleted a file by clicking shift + Delete+Enter and then you panic not knowing what to do next. The below steps will surely help you recover your lost files at once.
1. Keep Calm, (and I say this with enough emphasis).
2. Do not save anything anything on your hard disk as this might overwrite on the empty space created due to the deletion of your files and you might fail to recover those. (crucial step)
3. Download the software Recuva or any recovery software but its the best in my opinion.
4. Perform deep scan. It will take some some depending upon your PC configuration but its worth the time.
5. After scanning search for your desired files and select them carefully, if you have followed the above steps cautiously the chances of your files appearing with a green signal (implying its not corrupted) are high.
6 Hit the recover button , a pop-up window will appear saying that if you recover on your hard disk data might be lost so click on the no button.
7 Make sure you recover the files on another flash drive/external HDD/CD/DVD but not on your internal hard disk as it will again overwrite on the disk and the recovered file may get corrupted.
8. Select your external memory drive where you want to recover your files and then hit OK. Wait for the process to get over.
That's it. You have successfully recovered your permanently deleted files.