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How To Wipe Free Space On Windows PC

Are you looking for a solution to wipe free space on Windows PC? When you remove files from your hard drive? Did you know that the file never actually gets removed and is likely able to be backed up using tools like Recuva? Normally this isn’t a problem as we use our PC each day, however, if you’re want to sell your PC and don’t want your precious data to be backed up. Then follow the instructions below to clear the free space on your hard drive. The process is quite similar and will work on Windows 7, 8, and Windows 10.

What happens when you remove a file?

When you remove a file on your PC, the only thing that’s erased is the reference to it in the master file table. The file still available on your hard drive but Windows just doesn’t know where the file is. This is because as mentioned above, you’re only erasing the links or indexes to the data and telling Windows it has permission to overwrite that part of the hard drive.

So, until the data is written over, it can be backed up by special tools or the exact set of skills. The tools or an expert can scan the hard drive. Then view the files and backup links and indexes so Windows can view the files again. If you’re selling a PC or disposing of one, you should then clear the free space on your computer hard drive so that the files can’t be recovered.

Today we’ll learn how to use the cipher command on the command line to write over the free space many times to make sure no data can be backed up.

Wipe Free Space On Windows PC



Before using the command ‘cipher’ to securely or easily overwrite the free space on your hard drive, exit or close all programs.

Step 1:

Tap the Cortana icon or the Search icon on the Taskbar and initiate typing “command prompt.” Then, tap Command Prompt under the Best match.

Step 2:

Input the following command at the prompt and press Enter.

cipher /w:C

Data that is not assigned to any files or folders are overwritten and permanently erased. It takes a long time when you are overwriting a huge amount of free space.

Cipher goes through the following instructions as it securely wipes the free space:

  • It automatically creates a new folder on the C drive known as EFSTMPWP and then makes a file in the folder with nothing but 0 in it. It grows until the hard drive fills up.
  • Then, the cipher removes that file and makes another file. The file is filled with the number 255 repeatedly until the file grows large enough to fill the gap on the hard drive again.
  • Then, cipher wipes the other file, makes a third file, and fills that with random numbers until your hard drive is full again.
  • At last, the cipher removes the 3rd file and returns you to the prompt. Input exit at the prompt to exit the Command Prompt window.



If you’re not comfortable using a cipher, there’s a free utility known as CCleaner. It enables you to wipe the free space on your hard drive.

There are two variants of CCleaner, paid or free. The feature that clears the free space on your hard drive is available in the free variants.

Once you’ve installed the CCleaner or updated it. You can then open the program and tap Tools on the left pane. Then select the Free Space Only from the Wipe drop-down list. Keep in mind you DO NOT choose Entire Drive. This will wipe ALL the files on your hard drive—unless that is what you mean to do. If you’re getting rid of the computer, you can then use the Entire Drive option to clear the whole drive.

Select the type of overwrite method you need from the Security drop-down list. Simple Overwrite is good for some cases. However, if you like CCleaner to act like the cipher command. Then choose Advanced Overwrite (3 passes). At last, choose the drive to securely clear the free space in the Drives box. Then tap Wipe.


If you want to share any other method to securely overwrite free space then let us know in the comment section below! Waiting for your valuable feedback!

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