Have you ever wondered why you can recover deleted files? That’s a scary thought, isn’t it. Well, scary or helpful depending on your situation.
But the fact that deleted files, even those you emptied from the Recycle Bin, can be recovered means that there are some caveats to this whole file deletion process. What is it? Read to find out.
The file is not actually deleted
Rotary hard drives write in physical space. Windows marks this data with a pointer. The pointer indicates the start and end of the file storage process.
When you press the delete button, Windows only deletes those data pointers, the pointers that represent the start and end points of the data file. It does not delete the data file by itself.
Another way to see it is as an index of the files the OS keeps. Windows indexes all the files on your system. So instead of deleting the file, it just removes the entry from the index. For your system, it looks like you have more memory than before, but it’s not.
Deleting a data file takes a long time. Deleting the pointer for a 1 GB file takes a few seconds, but actually deleting the file takes a few minutes.
That’s why the system doesn’t mind it.
So you could say that the reason why files aren’t deleted when you explicitly say so is because your computer is too lazy.
So instead of deleting the file, the computer will lie there, waiting for you to download new content or copy something else. When it senses that something new is coming, it overwrites previously “deleted” files with new data.
Now, when the data file is overwritten, that’s when the file is actually deleted. Before that, the file could be recovered using file recovery software.
It’s not the same as SSD
Flash-based SSDs. Unlike hard drives, they don’t have spinning drives. I talked about their differences here.
Anyway, when it comes to SSDs that support TRIM, the data is erased instantly. Because unlike a hard drive, you cannot overwrite data on an SSD. You need to delete old data first to write new data.
This is why if you are using an SSD it will be much easier for you to delete files.
How to make sure your data is really deleted
If you have confidential data on your device that you really want to make sure it’s erased, download CCleaner. I’m sure you know all about CCleaner, the cleaning utility for Windows. However, the app also has an option to securely delete files.
The application does what Windows will do later. It overwrites the file instead of just deleting it.
For the Pros: CCleaner’s Data Eraser is a good tool, but it’s limited to drives. If you’re looking for more complex or feature-rich apps to delete individual files and folders, check out our guides to Eraser and SDelete.
In CCleaner, go to Tools -> windshield wiper and select the drive you want to erase. Here you can also specify security settings for the deletion.
After the official files are cleaned up, you have nothing to worry about. Most existing file recovery software depends on the file not being overwritten.
Categories: How to
Source: thpttranhungdao.edu.vn/en/
