Partitions Recovery

Partition is deleted or Partition Table is damaged

Consider the situations which cause a computer to hang up while booting or hang up due to data loss.

1. What will happen if no partition has been set to the Active state (Boot Indicator=0x80)?

Boot Indicator is removed from the first partition:

   0000001B0                                            00 01  ................   
   0000001C0 01 00 07 FE 7F 3E 3F  00 00 00 40 32 4E 00 00 00  ...?>?...@2N...

When trying to boot now, an error message like "Operating System not found" will appear. This means that the loader cannot determine which partition is a system and an active partition to pass control to.

2. What will happen if the partition has been set to an Active state (Boot Indicator=0x80) but there are no system files on that partition?

3. What will happen if a partition entry has been deleted?

4. What will happen if a partition entry has been damaged?

How can recovery software help you in the above-mentioned scenarios?

1. Discover and suggest which partition is to be set as active (FDISK also does this).
2. Perform a disk scan of the free space to look for a partition boot sector or remnants of deleted partition information in order to try to reconstruct the Partition Table entry for the deleted partition.
3. Perform disk scan on all space to look for partition boot sector or remnants of deleted partition information in order to try to reconstruct the Partition Table entry for the deleted partition.

Why is the partition boot sector so important?

It contains all the necessary information about the partition so that if recovery software finds it, it can reconstruct the partition entry in the Partition Table. (see Partition Boot Sector topic for details).

What would happen if a partition entry had been deleted then recreated with other parameters and re-formatted?

In this case, a new partition would exist instead of the original one. Everything would work properly with the exception that you could not go back to the original partition if important data is still there. If you've created a MBR, a Partition Table, or a Volume Sectors backup beforehand (as can be done with Active@ Partition Recovery and Active@ UNERASER for example), you can virtually restore it and look for your data (in the case it has not yet been overwritten by new data).

Some advanced recovery tools also have an ability to scan disk surfaces and try to reconstruct previously deleted partition information from the pieces of left over information (i.e. perform virtual partition recovery). However it is not guaranteed that you can recover something.