1)Build your recovery toolkit on your PC is before you lose any data.here is a choice for free tools like Recuva,PC Inspector File Recovery,Undelete Plus.
2)Install to USB flashDrive.The toolkit can be downloaded to and run directly from a flash drive.
3)the file itself isn't deleted even after emptying the Recycle Bin,instead, the first few bytes are altered to tell Windows that the space used by the file is now available for writing to. The rest of the file is left intact until it's overwritten with fresh data.So,there should be file deletion.
4)Pick the right search.
5)Cannot boot into windows,you could recover your data by plugging the drive into another PC.So that, data recovery outside windows.
6)Recover data from CDs/DVDs.
7)Recover corrupt files.

I failed to recover a deleted video, used every software, only one worked it was from Stellar, but paid software.

also, we can use "hard disk regenerator" if we have some bad on the hard disk ( a like bad sector ). With this tool we can repair hard disk bad sector and any error in the hard disk.