Partition Recovery

What is Partition?

Before we talk about partition recovery let’s make it clear what a partition is. In most simple words, it’s a logical division of a physical hard disk. The system recognizes and displays them as separate disks and you see them as disk “C:”, “D:, etc. in Windows (they are also called “volumes”). Partitions are created when you format a disk and in some cases significantly improve and optimize the work of your computer:

  • When you have several operating systems on you computer, you are recommended to install them on different partitions to avoid conflicts between different OS.
  • If your hard drive is large, you may want to define different cluster sizes for different partitions to optimize disk space usage, enhance computer performance and avoid disk space waste if you have many small files.

Let’s see how it works (we’ll take Windows XP as an example). The number or partitions, their size and location are defined in the partition table in Master Boot Record (MBR), located in the first sector of your hard drive. MBR is also responsible for booting process. The partition table may include up to 4 partition entries. These partitions are called Primary Partitions. But sometimes users need more than 4 volumes on the disk, for various reasons.

In such cases, instead of pointing to a single volume directly, a partition entry defined in MBR is pointing to Extended Partition Pointers (EPPs). An EPP block points to a volume (which is assigned a volume letter) and, optionally, to another EPP in the chain. In this way, a hard drive can be divided into a large number of volumes, until you run out of letters or disk space. Together, MBR and EPPs are called Partition Tables.

When you need a partition recovery?

  • Accidental deletion of a wrong volume which actually means the deletion on pointer to the volume, while the information remains intact.
  • In some cases a pointer to a logical disk can be broken and the disk is lost. Accordingly, if there are other volumes in chain under that logical drive, they will become inaccessible as well.
  • In more serious cases (often caused by viruses) the boot sector may be damaged with all partition tables gone.

If data loss has already occurred, we recommend to have a look at the brief data file recovery guide, that can help you avoid critical mistakes and prevent total data loss.

Successful partition recovery is based on finding out the size, the location and boundaries of the lost volumes. That is why the case with a disk containing a single logical drive is relatively simple. It can be assumed that the lost volume occupied the whole hard drive and the rest is done with recovery software. The slight difference in boundaries of the lost and the assumed volume is possible, but that won’t matter in this case. If the hard drive contains many logical drives, the situation is worse, especially if the damage occurred to MBR or somewhere at the beginning of the EPP chain. Use special partition recovery software to restore lost partitions.

Partition Recovery Tip

There are ways of manual partition recovery. However, that includes some assumptions and partition recovery may not be exact.