Shift+Delete

Do you need to recover lost files, photos or documents? You're sure that a file was on your hard disk some time ago, but now it seems to have disappeared. Perhaps you archived some files or photos to CD or DVD to save disk space, and now the disk is corrupt or unreadable? Or perhaps your computer won't boot up, and you don't have a backup!

It may seem as if all is lost. But don't panic! Your data is almost certainly still on your hard drive somewhere. This article will help you choose the best method for restoring them.

Accidental deletion is the most common cause of lost data. Modern operating systems provide protection against accidentally deleting files. In Windows, it's called the Recycle Bin. It's basically a special folder to which files are moved when they are deleted. As far as the operating system is concerned files that are deleted to the Recycle Bin are not really deleted at all. If you think you have deleted a file, the Recycle Bin should be the first place that you look.

If you empty the Recycle Bin, or Shift+Delete a file, then the file becomes deleted as far as the operating system is concerned. The file disappears from any folder listing and the disk space occupied by the data becomes available for re-use. But the data is not physically erased from the disk. The disk space still contains the data. And it is not re-used immediately. What data recovery products do is find ways to locate this data so that the files can be undeleted or unerased
When files are deleted, a lot of pointers to the data are still left lying around. Because of this, recovering deleted files can be treated as a special case as far as data recovery goes.
It's a lot quicker than a full data recovery, which requires locating the contents of lost files with no additional pointers at all. Some data recovery tools will only recover deleted files.

Recovering photos

Specialist data recovery software can speed up the process and improve the chances of success by searching just for specific file types. . Using forensic techniques they can locate lost files on otherwise unrecoverable disks.

Photo recovery software will know, for example, that a JPG image file will start with the characters "JFIF". Following that is a header that gives more information about the file, such as its length. The software will scan the disk looking for a cluster that starts with "JFIF", determine the expected file length, and then read as many clusters as necessary to create a file of that length.

However, the recovered images will be corrupt if the file was fragmented. Because the data stream in a photo image file is essentially random, it isn't as easy to piece together a file from fragments in the way that you can for a text-based document.