What Softwares/techniques data recovery professional use to recover data from HDD ?

[CadCrazy]

The data recovery professional charge hefty sum to recover data from hard disk in case of crash. I want to know can't we do this at home. What software/procedure they use to recover ??????

 

[Choto Cheeta]

Search my frnd search... atleast 100 thread on it asking same question here at Digit forum searching will help