Recover Data From Formatted Disk
Posted on Sep, 22, 2017
We all believe that when a disk is formatted it deletes all its data and goes blank. As a result, there is no data left behind and the formatted disk is considered as clean as it has never been used. However, this is a misconception and is not always true. Almost all hard drives use a similar mechanism to store and delete data from it. The way in which the data appears to be deleted makes it possible to recover the deleted data through various professional software. There are various tools that can be used to recover data from formatted disks.
The details about the file and its contents are stored separately on the disk. This is to utilize the disk space in the best possible way. It can be compared with a book, which uses an index or table at the beginning to locate the content easily that a reader looks for. Similarly, disk stores information about the files in the form of a table. Information such as filenames, folder paths, the location of actual content, etc. is stored in the table.
Windows uses the File Allocation Table (FAT) and Master File Table (MFT) for its FAT and NTFS file systems respectively. These tables contain the majority of the information related to file and folder structure. However, there could be few other locations that hold such information.
Formatting a Disk
A disk can be formatted by either ‘Quick Format’ or ‘Full Format’. While performing a quick format of the disk a new file is created, this replaces the old FAT or MFT. The format operation completely or partially overwrites the FAT or MFT table, which will wipe various information that as previously written including filenames, folder structure and the physical location of the data. However, the data still remain intact in its location, until it is overwritten by any other write operation.
Performing a full format is similar to quick format, as the existing table of the file will be overwritten by the new one. This operation performs an additional task of checking the disk for bad sectors and is recommended while installing a new OS. In case the system was formatted using Windows XP, the data will remain intact. But, in case of Windows Vista, Windows 7, and any later versions, the disk will be overwritten completely, making the data beyond the scope of recovery.
Analyzing all the situations discussed above, any formatting operation affects the file table, keeping the data unaffected. The data that has been deleted due to quick format or due to formatting by Windows XP, can be easily recovered. In order to ensure a safe and complete data recovery, it is advised not to use the affected drive. Else, you must run the recovery software before the data is overwritten by any write operation.
Note: Drives that are completely formatted by Windows Vista using the “secure format” option, cannot be recovered, as it erases the residual data. You can look for a professional tool to recover lost data from other scenarios.