When a partition table gets deleted, corrupted or lost in general, only its entry is removed from first sector of the hard drive; and although the data is no longer available, it still remains on the disk pending to get overwritten. Expert recovery tools can locate lost file systems even if partition table information is missing. Irrespective of the file system and operating system, partition table is always the first physical sector of a hard drive which starts from 0, 0 and 1 which means the 0th cylinder, a 0th head and the 1st sector.

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A partition table resembles the map of a township which refers to a block as residential or playground. In similar fashion we have start and end points marked inside 512 bytes. The partition table holds the information about a boot loader, also marking the bootable logical drive as active partition. Partitioning makes it possible to create several file systems (either of the same type or different) on a single hard drive.

Theoretically, a hard disk should contain up to four primary partitions, or one to three primary partitions along with a single extended partition. Further we can create logical drives in the extended drive. This procedure is followed in MS-DOS partitions created using FDISK.

A primary (or logical) partition contains one file system. MS-DOS and earlier versions of Microsoft Windows systems, the first partition (C must be a “primary partition". Other operating systems may not share this constraint.

For example, under either DOS or Windows, a hard disk with one primary partition and one extended partition, the latter containing two logical drives, would typically be assigned the three drive letters: C:, D: and E: (in that order). Drive letter A: and B: are reserved for floppy drives.

Other than FDISK there are other popular third-party partition management programs available such as Acronis True Image, Norton Partition Magic, Norton Ghost, or specialized recovery programs that come with computers manufactured by most major manufacturers. Windows NT / 2000 / XP / Vista includes an inbuilt ‘Disk Management’ program which allows for the creation, deletion and movement of partitions.

For Unix-based operating system such Solaris, SCO Open Server, SCO UnixWare, IBM AIX or Linux the partitions are created with name of partition instead of drive letter for e.g. /boot, /home, /tmp, /usr, /var, /opt, swap and all remaining files under the “/” (root directory). Such a scheme has a number of potential advantages: if one file system becomes corrupted, the rest of the data (the other file systems) stay intact, minimizing data loss.

Briefly it would be much clearer now that MBR (Master Boot Record) consists of Partition table and a first copy of the boot sector of an active partition. The loss of MBR does not mean data loss. Data is intact and is on offering with the help of any good data recovery application it can be escorted out from this partition can be moved to a healthy drive. I must say a very important thing about one category of applications which were quite popular for some time “Partition Repair” tools. They are the most dangerous set of tools available and would create extremely complex problem for a data recovery technician which could have been a piece of cake kind of recovery for any good recovery software.

Most importantly we go for such tools because we are looking to restore everything if we are able to repair the partition table (a shortcut to heaven) to get back system with all settings, applications and most importantly Operating System which might prove a day’s job to rebuild. Let me tell you if you use applications such as Acronis True image or Norton Ghost then you need not worry about such problems. You just need to keep one image as a factory setting (First Installation Image) of either the first partition or of complete drive and keep on updating another one after every fortnight (that is minimum you could do with taking backup, however there are more things which can be implemented to take the most latest backup with lot of restoration options).