After the last part everyone has been very interested in this. Many have given the right answer to the question. Yes, files can be recovered. But why? I deleted the file, so how can it be recovered? That is what we will discuss today. But for that you really do have to read the previous part first.
Statutory warning — spoiler alert
This is the second part. If you come here without reading the first part you will not understand it, because there is no recap. And if you read the first part after the second, you will not enjoy it at all. So I request you: read the previous part first. Then read this one 😀 Link to the first part: Where Do Deleted Files from a Memory Card or Hard Drive Go?
Finished reading? Then let's begin. From the previous part this much is clear: how, when a new file arrives, new pointerless space takes on new data. So suppose I now delete a file and do not add a new one — that is, I put no other data into the so-called empty space. In that case can I recover that file? After all, that space has not been replaced by any new data.
Yes, certainly! In this way you can easily (read: fairly easily 😐) recover the file you need. In fact I did not know this before either. A few years ago, when one fellow emptied a whole Linux command — with the help of Linux commands he emptied an entire hard disk and recovered it. That is when I learned this could be done. That said, a compressed file usually ends up corrupt. Audio and video stay more or less intact. Why not compressed files? Because if just a few bits there go astray, the file becomes corrupt or does not work. That is why there is trouble with software and other such things. But with something like audio or video, a few bits going astray causes no problem.
Let me give a good example to make this clear. Suppose you download half of a compressed file (let's say an Android APK file) and try to install it. Will it work at all? Impossible — never. On the other hand, if you download about half of an audio or video file, you can listen to or watch as much as you have downloaded (the arithmetic is different with multiple connections). If you do not believe it, try it today.
Anyway, if we go this deep the discussion will take a lifetime to finish. Let's come back to where we were. The question is: why can all files not be brought back completely intact? Because once your file is deleted its pointers are gone, so it becomes hard even to tell which bits made up the deleted file. Suppose you had rice, lentils and spices. Delete all three and they mix together into khichuri. Separating the rice, lentils and spices out of that is rather hard work. But some data-recovery software does that hard work tirelessly. My humble respects to them (😜).
Now, how much of a file can be recovered depends on your file system. For example, the Windows NTFS or NTFS file system keeps the pointer information for a file even after that file is deleted. As a result it becomes much easier for any recovery software to find the file. Other file systems, such as UTF or UTF or FAT or FAT erase a file's pointer information the moment the file is deleted. As a result it becomes much harder for recovery software to find the file.
Everyone's eye is now on the last question: which recovery software should I use? There are a great many of them, some free and some paid. Clearly the paid ones will have more features — that is only natural. But if you are an ordinary person like me, free will do. Where do you find them? Google ‘Free Data Recovery Software for Windows 64 Bit‘ (if your PC is 32-bit, write 32 Bit). Use whichever you like. If you really cannot find one, let me know.
That is all for today. If you have any questions you can say so in the comments — or if you have a comment about the two posts, tell me that too. The next post will probably be about IP addresses or VPNs. If you have any technology question, you can suggest it. If I know the answer I will write an article about it, insha'Allah.
