PhotoRec dan TestDisk adalah dua perisian yang boleh digunakan untuk mengembalikan semula data yang telah terpadam atau hilang contohnya akibat gangguan eletrik terhadap sistem komputer.  Kedua-duanya diedarkan di bawah GNU Public License yang membenarkan penyalinan semula dan pengedaran.  Pengguna yang berminat untuk menggunakan perisian ini bolehlah muat turun dari http://www.cgsecurity.org/wiki/PhotoRec dan http://www.cgsecurity.org/wiki/TestDisk.

A.   PhotoRec, Digital Picture and File Recovery

PhotoRec is file data recovery software designed to recover lost files including video, documents and archives from Hard Disks and CDRom and lost pictures (thus, its ‘Photo Recovery’ name) from digital camera memory. PhotoRec ignores the filesystem and goes after the underlying data, so it will still work even if your media’s filesystem has been severely damaged or re-formatted.

PhotoRec is free, this open source multi-platform application is distributed under GNU Public License. PhotoRec is a companion program to TestDisk, an app for recovering lost partitions on a wide variety of filesystems and making non-bootable disks bootable again. You can download them from this link.

For more safety, PhotoRec uses read-only access to handle the drive or memory support you are about to recover lost data from. Important: As soon as a pic or file is accidentally deleted, or you discover any missing, do NOT save any more pics or files to that memory device or hard disk drive; otherwise you may overwrite your lost data. This means that even using PhotoRec, you must not choose to write the recovered files to the same partition they were stored on.

Operating systems

PhotoRec runs under:

* DOS/Win9x
* Windows NT 4/2000/XP/2003/Vista
* Linux
* FreeBSD, NetBSD, OpenBSD
* Sun Solaris
* Mac OS X

and can be compiled on almost every Unix system.

http://www.cgsecurity.org/wiki/PhotoRec

B.   TestDisk, Data Recovery

TestDisk is OpenSource software and is licensed under the terms of the GNU Public License (GPL).

TestDisk is a powerful free data recovery software! It was primarily designed to help recover lost partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software, certain types of viruses or human error (such as accidentally deleting a Partition Table). Partition table recovery using TestDisk is really easy.

TestDisk can

* Fix partition table, recover deleted partition
* Recover FAT32 boot sector from its backup
* Rebuild FAT12/FAT16/FAT32 boot sector
* Fix FAT tables
* Rebuild NTFS boot sector
* Recover NTFS boot sector from its backup
* Fix MFT using MFT mirror
* Locate ext2/ext3 Backup SuperBlock
* Undelete files from FAT, NTFS and ext2 filesystem
* Copy files from deleted FAT, NTFS and ext2/ext3 partitions.

TestDisk has features for both novices and experts. For those who know little or nothing about data recovery techniques, TestDisk can be used to collect detailed information about a non-booting drive which can then be sent to a tech for further analysis. Those more familiar with such procedures should find TestDisk a handy tool in performing onsite recovery.
Operating systems

Operating systems

TestDisk can run under

* DOS (either real or in a Windows 9x DOS-box),
* Windows (NT4, 2000, XP, 2003, Vista),
* Linux,
* FreeBSD, NetBSD, OpenBSD,
* SunOS and
* MacOS

Source files and precompiled binary executables are available for DOS, Win32, MacOSX and Linux from the download page

http://www.cgsecurity.org/wiki/TestDisk