Below numbering of the seven disastrous faults not to do while your hard disc is damaged.
1- Encase of fire harm don't try to clean, or to put in refrigerator or deep freezer on fire damaged media.
2- Encase of physical harm don't attempt to remove disc drive, don't shake, dismantle any hard disk or notebook that has been damaged, since wrong handling can do retrieval more serious or impractical.
3- After physical harm immediately switch off PC, never try to operate whatsoever visible damaged devices as additional operation may harm data irremediably.
4- Water harm case : Never ever try to make clean or dry out water damaged hard drive by opening it or disclosing it to heat (the high temperature of a hair drier for instance).
5- Once a user check messages such as "Operating System not found", "Corrupt Volume" or once he may merely be missing files and folders he had better at once shut down the computer. (Since the more durable a damaged hard disk is left working, the many more data that can be entirely dropped off).
6- Encase of mechanical harm if you pick up strange makes noise or grinding, don't carry a check disk software package (CHKDSK or some another software like that).
7- And at last if you're a newcomer, never set about to try the retrieval alone whenever you have some valuable data.
In this seven sort of case you'll have to get through narrowed down company, and that can/will cost you in all probability a good deal of money.
As a matter of fact the biggest erroneous belief to stave off is the absence of backup, I'll never say it sufficient, backup your files, backup your files... Backup...
Or get fix to confront a catastrophe.