How to check if my file is recoverable by myself?

You can open your file with a hexadecimal editor and check its data. If the file is filled with all zeros, then your file is beyond recovery.

There are many hexadecimal editors available:

  1. (Free online editor)
  2. OnlineHexEditor (Free online editor)
  3. Hex Works (Free online editor)
  4. UltraEdit (Windows Application, Shareware)
  5. WinHex (Windows Application, Shareware)