In this article we want to focus on what you should do and what you should not do when recovering deleted files. However, we don’t just want to tell you what to do (and what not to do); we also want you to understand why!

Consequently, before we discuss Deleted File Recovery Do’s and Deleted File Recovery Don’ts we need to provide a bit of background information – just follow along and your understanding should begin to flourish in no time!

The Computer File

Before we go too far we need to discuss the computer file a little bit.

What is a file? Most of us know exactly what a file is! It’s an icon on our computer which, when double clicked, displays a Microsoft Word document, or a picture of our last vacation, or a movie of the wedding we just went to… etc. In other words, it is a graphical wrapper around a bunch of information.

How is a file stored on our computer? Although we may see a text document, picture, or movie; our computer only sees a bunch of 1’s and 0’s (binary). It is our operating system (Microsoft Windows or Mac OS X) which transforms these 1’s and 0’s into what we see on our monitor.

How are files organized? When we double click on a file to open it, how does our computer know which 1’s and 0’s to look at in order to show us the appropriate information? It is actually the file system who manages this relationship between the 1’s and 0’s on our computer, and the graphical items on our monitor. Think of the file system as a humongous table of contents.

Computer File

File Deletion

Now that we have basic knowledge about files, file systems, and operating systems let’s look at the process of file deletion.

When we send a file to the recycling bin and empty it:

  • The operating system tells the file system that the file is no longer needed.
  • The file system subsequently forgets about the file (the file is  removed from the humongous table of contents).

It is very important to notice that the file system doesn’t immediately kill the deleted file (by writing a bunch of random 1’s and 0’s over it), it only forgets about it. In fact, the deleted file isn’t actually deleted until a new file is created on top of it!

Deleted File

Deleted File Recovery

Knowing what we now know, how are deleted files recovered?

Remember that when you send a file to the recycle bin and then choose to empty it you are not actually deleting the file – rather, you are simply telling the file system (that humongous table of contents) to forget about that file. From this statement we can conclude that the goal of file recovery is to find deleted file(s) without the help of the file system.

Now you or I can’t go through our computer looking for all of the 1’s and 0’s which correspond to a file which was just emptied from the recycle bin. Such a task would be impossible since we would have to know the answers to important questions such as:

  • Where should we start looking for the file?
  • Where should we stop looking for the file?
  • How many 1’s and 0’s make up the file?

Luckily there are computer experts who have created specialized programs, data recovery programs, which can perform the tasks mentioned above. A data recovery program follows this general pattern:

  1. It begins by asking you what type of files you want to recover
  2. It proceeds to ask you where the files you want to recover are/were located.
  3. It searches a specific area of your computer (specified by Step 2) for specific types of files (specified by Step 1).

deleted file recovery

Deleted File Recovery: A Simple Example

Assume that you just accidentally deleted a Microsoft Word document from a USB and you wish to recover it. Here is the general process which would occur.

  1. You would begin by downloading a data recovery program.
  2. You would tell the data recovery program that you wish to recover Microsoft Word files (since this is what you accidentally deleted).
  3. You would tell the data recovery program that you wish to recover files from the USB (since this is where the file was accidentally deleted).
  4. The data recovery program would go through your USB key and look for any groups of 1’s and 0’s which are not in the file system and which form the structure of a Microsoft Word file. How does the data recovery program know which 1’s and 0’s correspond to a Microsoft Word program? Built into every data recovery program is a set of signatures – think blueprints – which tell it what different types of files should look like. Consequently, it knows what pattern to look for when searching for: Word documents, JPEG photos, MP3 music files, MPEG movie files … etc.

Deleted File Recovery Do’s

 Here is what you should do when attempting to recover deleted files.

  • Do attempt to recover deleted files as soon as possible: The sooner you attempt to recover a deleted file, the less chance that it will be overwritten, permanently, by a new file.
  • Do make use of data recovery software: You will be unable to recover deleted files manually – plain and simple. In order to perform such a task you are going to need to download a data recovery application; examples include:  Recuva, MiniTool Power Data Recovery, PhotoRec, and R-Undelete.
  • Do make use of computer repair experts and data recovery specialists if need be: If you are completely uncertain as to how to proceed or you are unable to recover your deleted files then talk to a computer repair expert or data recovery specialist. In many cases they can help you out (for a price of course).
  • Do back up your files often: Just as a quick reminder; a file which is backed up need never be recovered! Unfortunately, backing up is only helpful as a preventative measure.

Deleted File Recovery Don’ts

 Here is what you should not do when attempting to recover deleted files

  • Do not continue to use a device after you accidentally deleted files from it: This is very important. The longer you wait to recover a deleted file, the greater the chance that it will be overwritten by a new file (destroying it permanently). Therefore:
    • If the deleted files you wish to recover are on your C: drive (or in your recycle bin) then shut down your computer – and don’t turn it back on!
    • If the deleted files you wish to recover are on an SD card then take the SD card out of your digital camera – and don’t use it!
    • If the deleted files you wish to recover are on a USB key then stop using the USB key!
    • If the deleted files you wish to recover are on an external hard drive then stop using the external hard drive!
    • If the deleted files you wish to recover are on a CD or DVD then stop using the CD or DVD!
  • Do not install programs onto a device where deleted files, which you wish to recover, reside: This is very important. If you install programs onto a device where deleted files reside then you are increasing the likelihood that the deleted files will be overwritten (destroying them permanently). Therefore:
    • Do not install any programs onto your local hard drive (C: drive) if deleted files are on your local hard drive (including in your recycle bin).
    • Do not install any programs onto an SD card if deleted files are on that SD card.
    • Do not install any programs onto a USB key if deleted files are on that USB key.
    • Do not install any programs onto an external hard drive if deleted files are on that external hard drive.
    • Do not install any programs onto a CD or DVD if deleted files are on that CD or DVD.
  • Do not recover files onto a device where deleted files, which you wish to recover, reside : This is very important. If you recover files onto a device where deleted files reside then you are increasing the likelihood that the deleted files will be overwritten (destroying them permanently). Therefore:
    • Do not recover any files onto your local hard drive if deleted files are on your local hard drive (including in your recycle bin).
    • Do not recover any files onto an SD card if deleted files are on that SD card.
    • Do not recover any files onto a USB key if deleted files are on that USB key.
    • Do not recover any files onto an external hard drive if deleted files are on that external hard drive.
    • Do not recover any files onto a CD or DVD if deleted files are on that CD or DVD.
  • Do not attempt to recover deleted files by yourself if you are uncertain how to proceed: If you are completely uncertain as to how to proceed then don’t attempt to recover your deleted files by yourself – contact a computer repair expert or data recovery specialist.

Summary

Hopefully by now you have a reasonable idea as to how the recovery of deleted files occurs. However, even if you do not – that is OK.

The one thing we really want you to take away from this article is the list of Deleted File Recovery Don’ts. These are the golden rules which will prevent your deleted files from being lost permanently!

Finally, remember that if you are at all unsure of what you are doing feel free to email us here at Seymour Computer Repair. We have helped many people recover lost files – maybe we can even help you :]