TestDisk is aimed at recovering lost partitions, making non-booting disks bootable due to software issues, viruses as well as human error.

This utility is designed to be easy for partition table recovery. It can repair a partition table, recover deleted partitions, recover FAT32 boot sector from its primary backup, rebuild FAT12/FAT16/FAT32 boot sector and fix FAT tables. You can also rebuild an NTFS boot sector, recover NTFS boot sector from its backup, fix MFT using MFT mirror and locate ext2/ext3/ext4 Backup SuperBlock. Additionally, you are provided with the capability to undelete files from exFAT, ext2 filesystems, FAT, NTFS, and copy files from deleted exFAT, FAT, NTFS and ext2/ext3/ext4 partitions.

TestDisk will appeal to novice and expert users alike with features for both. For novice users that have little experience with data recovery techniques, TestDisk can be utilized to gather comprehensive data about a non-booting drive that can be provided to an experienced user on a support forum or an IT professional. And for those advanced users familiar with the area will find it to be a useful tool for performing onsite recovery.

TestDisk can find lost partitions for all of these file systems:

BeFS ( BeOS )
BSD disklabel ( FreeBSD/OpenBSD/NetBSD )
CramFS, Compressed File System
DOS/Windows FAT12, FAT16 and FAT32
HFS and HFS+, Hierarchical File System
JFS, IBM's Journaled File System
Linux Ext2 and Ext3
Linux Raid
RAID 1: mirroring
RAID 4: striped array with parity device
RAID 5: striped array with distributed parity information
RAID 6: striped array with distributed dual redundancy information
Linux Swap (versions 1 and 2)
LVM and LVM2, Linux Logical Volume Manager
Mac partition map
Novell Storage Services NSS
NTFS ( Windows NT/2K/XP/2003/Vista )
ReiserFS 3.5, 3.6 and 4
Sun Solaris i386 disklabel
Unix File System UFS and UFS2 (Sun/BSD/...)
XFS, SGI's Journaled File System