In personal computers, a partition is a logical division of a hard disk created so that you can have different operating systems on the same hard disk or to create the appearance of having separate hard drives for file management, multiple users, or other purposes.

For example, you can have all Windows system files on one partition (represented as Drive C: in Explorer) and all your data in data partition (shown as Drive D: in Explorer).

The process of partitioning of a hard disk is done by either a manufacturer or when you format a disk. Each partition contains system area and user data. As it is shown on the picture, in the beginning of a partition is located Boot Sector - a small system header describing partition size, type etc. Another system area us MFT which contains description of all files in the partition and their relationship. The rest is occupied by user files themselves.

It is worth noting that the very first sector of a hard disk contains a very important system block called MBR (Master Boot Record) which enumerates all partitions on the disk, their size and location.

When Windows is booting, it reads MBR and obtains information about partitions present on the hard disk. If for some reason the data in MBR is corrupted, Windows would not be able to get access to files in those partitions. If we're talking about system partition - Windows simply wouldn't load; as for data partition - you wouldn't be able to get access to any of your file.

Despite being so critical, MBR data is not protected well and can be easily damaged by a virus or simply a hardware failure. Taking into consideration that MBR is accessed many times every day, it is not a wonder that one of the disk operation might damage it.

What happens when MBR is get damaged? Actually all the data (system and user files) are remain intact but the whole partitions with them are not accessible. Computer simply takes the whole hard disk as sequence of meaningless bytes, as garbage and doesn't know what to do with them.

The best solution in such emergency situation is to use a special data recovery tool called Active@ Partition Recovery. While being able to perform multiple recovery tasks its major benefit is ability to scan hard disk and detect lost partitions which are otherwise not existent. Once Active@ Partition Recovery finds partitions, it can rebuild or restore MBR and Windows will start seeing data as it was before the damage. The best thing in this solution is that you can trust your restored data and continue to use restored partitions as before (because partitions themselves were not damaged, only MBR). Similar situation may happen with Boot Sector also. The solution is the same - use Active@ Partition Recover as soon as possible.

A word of warning. If all your partitions suddenly have gone and disk appears empty, it's probably a sign of damaged MBR. Do not format disk and don't try recover individual files. Avoid ANY writing to the disk; thus you will save partitions from being damaged. Get Active@ Partition Recovery as soon as possible, launch it from a Boot Disk and make it scan the hard disk. There are good chances that you'll get 100% data back.

Alex Schneider