TestDisk is a free and open-source data recovery utility that helps users recover lost partitions or repair corrupted filesystems.

[4][3] TestDisk retrieves the LBA size and CHS geometry of attached data storage devices (i.e. hard disks, memory cards, USB flash drives, and virtual disk images) from the BIOS or the operating system.

TestDisk reads sectors on the storage device to determine if the partition table or filesystem on it requires repair (see next section).

[3] It can mount various types of disk images including the Expert Witness File Format used by EnCase.

He is also responsible for the packaging of TestDisk & PhotoRec for DOS, Windows, Linux (generic version), MacOS X, and Fedora distribution.