-> What 'delete means
->What actually happens when you 'delete'
->Why deleted files arent erased immediately
->How to recover
What does ‘delete’ mean????
Many still believe that when deleting a file on their computer, it vanishes into thin air. But thats not the case .If you simply press the delete button,the operating system simply remove it from the file list and makes the files space available for new data to be stored, ie: the operating system doesnt zero or clean the space the file was using. It is simply marked as empty.Deleting a file is the equivalent of turning to the contents page of a book and marking a chapter as empty, even though the actual chapter still exists.
What actually happens when you 'delete'???
Windows (and other operating systems) keep track of where files are on a hard drive through “pointers.” Each file and folder on your hard disk has a pointer that tells Windows where the file’s data begins and ends.
When you delete a file, Windows removes the pointer and marks the sectors containing the file’s data as available. From the file system’s point of view, the file is no longer present on your hard drive and the sectors containing its data are considered free space.
However, until Windows actually writes new data over the sectors containing the contents of the file, the file is still recoverable. A file recovery program can scan a hard drive for these deleted files and restore them. If the file has been partially overwritten, the file recovery program can only recover part of the data.
Why Deleted Files Aren't Erased Immediately???
If you’re wondering why your computer doesn’t just erase files when you delete them, it’s actually pretty simple. Deleting a file’s pointer and marking its space as available is an extremely fast operation. In contrast, actually erasing a file by overwriting its data takes significantly longer. For example, if you’re deleting a 10 GB file, that would be near-instantaneous. To actually erase the file’s contents, it may take several minutes – just as long as if you were writing 10 gigabytes of data to your hard drive.
To increase performance and save time, Windows and other operating systems don’t erase a file’s contents when it’s deleted. If you want to erase a file’s contents when it’s deleted, you can use a “file-shredding” tool – see the last section for more information.
Solid-State Drives Work Differently: None of this applies to solid state drives (SSDs). When you use a TRIM-enabled SSD (all modern SSDs support TRIM), deleted files are removed immediately and can’t be recovered. Essentially, data can’t be overwritten onto flash cells – to write new data, the contents of the flash memory must first be erased. Your operating system erases files immediately to speed up write performance in the future – if it didn’t erase the file data immediately, the flash memory would first have to be erased before being written to in the future. This would make writing to an SSD slower over time.
How to recover ???
Nowadays, there are actually several ways of recovering 'deleted' files.From all the above now you know your data isnt gone, and its still there. For data recovery we mainly use software. They range from free softwares to highly paid ones. I'll list each one of them according to their file recovery capability and price
1) Recuva ( Free ) :-
A free software, tiny and free one can recover files, that includes files emptied from the Recycle bin as well as images and other files that have been deleted by user error from digital camera memory cards or MP3 players. It will even bring back files that have been deleted from your iPod, or by bugs, crashes and viruses!
Download it from here
2) Panda Recovery(Free ) :-
Pandora Recovery actually recovers files permanently removed from Recycle Bin, files originally deleted using Shift + Delete keys bypassing Recycle Bin and files deleted from DOS prompt. Pandora Recovery allows you to find and recover recoverable deleted files from NTFS-formatted volumes, regardless of their type - you can recover pictures, songs, movies or documents.
Download it from here
3) EaseUS ( Free & Paid) :-
There are 4 variants for it. Data Recovery Rizard Free (Free) , Data Recovery wizard pro(69.95$),Data Recovery Wizard Pro with Bootable Media (99.95$) ,Data
Recovery Wizard Technician(499$) As their price increases, so do their functions.I personally recommend Data recovery Wizard Pro. Download it from here
4) Stellar Phoenix ( Free & Paid) :-
These guys has made too many variants that its very difficult to write them down. I recently installed Ubuntu 13.10, did something foolish, lost all partitions and data, formatted the drives twice,installed windows 7. But the real pain was in loosing photos, i bought this software, took almost 7 hours, got all my 13Gb photos without a scratch
Download it from here
EaseUS and Steller does also provide partitions recovery tools.
An extra tip for you all guys.
How to get rid of "Deleted" files???
1) OVERWRITING THE FILE.... You keep adding new data to it until it becomes unrecognizable. However, overwriting doesn't always work. Some people have overwritten files more than 35 times and even then hackers and cyber criminals have been able to piece the information back together.
2) There is a software called Super shredder, it actually zeroes the sectors that the file was using.
You can download it from here http://www.softpedia.com/get/Security/Secure-
cleaning/SuperShredder.shtml and Also Ccleaner can also be used to wipe an entire drive Ccleaner->Tools->Drive wiper-> Change wipe to entire drive and security to how many passes you need ( more the passes, increased chances to removing the files and lesser chance of recovering it and increased time for process)
If you have doubts or questions reply to me.