One may ask the enigmatic question: how is data stored on a hard drive? Well, inside a hard drive there’s a disk platter that spins very fast (up to 10,000 RPM) and it has “heads” to read and write to this platter just like an old record player. The disk has these things called “sectors.” These “sectors” are little spaces on the disk and that is where the data on your computer is stored. When data is deleted, the disk marks that sector with a line of code which tells the system you can rewrite over this sector.
If you rewrite over these sectors the possibility of recovering the data that was deleted is less likely to recover. We recommend to anyone with very important data is when you have a very serious problem like: missing files, the system not booting, or your programs mysteriously not executing is to turn the machine off and do not use it. Bring it in as soon as possible so that the disk will not be damaged anymore. These symptoms are tale tell signs of a hard drive on its way out.
The possibility of the data recovery is much higher when the disk does not endure any stress to it and increases the chance of a successful recovery.