Using TestDisk and PhotoRec.

TestDisk can recover lost partitions of virtually any filesystem. PhotoRec can recover files of most types, including most picture and video formats. PhotoRec can be used on existing partitions, or can be used to recover files on deleted partitions without having to recover the underlying partitions. Both PhotoRec and TestDisk can be run on DOS, Windows (9x, NT, 2000, XP, 2003), Linux, FreeBSD, NetBSD, OpenBSD, Sun Solaris, and Mac OS X, and, their developers claim, can be compiled and run on most Unix systems.

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