Recover Data Files, Unerase Files

Information stays on a formatted hard-drive until it is overwritten with fresh data. The act of formatting the drive or deleting data merely removes the markers that tell the computer not to store information in that particular location. Although, re-formatting a drive makes information harder to recover than if a file is merely deleted, the only way to be absolutely certain that a file is unrecoverable is too physically destroy the drive or expose it to powerful magnetic fields.

the fat is destroyed so the data remains there, and in all devices (pendrives, mp4) with architecture.. some programs like r-studio make possible to recover the information, in windows is more easy because the windows make a copy of fat.. in linux the way to save the things is different and you dont have desfragmentation (is this the name in english? sorry ) … for all , Ubuntu is the best (and is free of shure)

Recovery techniques
Recovering data from physically-damaged hardware can involve multiple techniques. Some damage can be repaired by replacing parts in the hard disk. This alone may make the disk usable, but there may still be logical damage. A specialized disk-imaging procedure is used to recover every readable bit from the surface. Once this image is acquired and saved on a reliable medium, the image can be safely analysed for logical damage and will possibly allow for much of the original file system to be reconstructed.

Hardware repair
Examples of physical recovery procedures are: removing a damaged PCB (printed circuit board) and replacing it with a matching PCB from a healthy drive, performing a live PCB swap (in which the System Area of the HDD is damaged on the target drive which is then instead read from the donor drive, the PCB then disconnected while still under power and transferred to the target drive), read/write head assembly with matching parts from a healthy drive, removing the hard disk platters from the original damaged drive and installing them into a healthy drive, and often a combination of all of these procedures. Some data recovery companies have procedures that are highly technical in nature and are not recommended for an untrained individual. Any of them will almost certainly void the manufacturer’s warranty.

Disk imaging
The extracted raw image can be used to reconstruct usable data after any logical damage has been repaired. Once that is complete, the files may be in usable form although recovery is often incomplete.
Open source tools such as DCFLdd or DOS tools such as HDClone can usually recover data from all but the physically-damaged sectors. Studies have shown that DCFLdd v1.3.4-1 installed on a Linux 2.4 Kernel system produces extra “bad sectors” when executed with certain parameters, resulting in the loss of information that is actually available. These studies state that when installed on a FreeBSD Kernel system, only the bad sectors are lost. DC3dd, a tool that has superseded DCFLdd, and ddrescue resolve this issue by accessing the hardware directly. Another tool that can correctly image damaged media is ILook IXImager, a tool available only to government and Law Enforcement.