SystemRescueCd is a linux system on a bootable cdrom for repairing your system and your data after a crash. It also aims to provide an easy way to carry out admin tasks on your computer, such as creating and editing the partitions of the hard disk. It contains a lot of system utilities (parted, partimage, fstools, ...) and basic ones (editors, midnight commander, network tools).
It aims to be very easy to use: just boot from the cdrom, and you can do everything. The kernel of the system supports most important file systems (ext2/ext3, reiserfs, reiser4, xfs, jfs, vfat, ntfs, iso9660), and network ones (samba and nfs).