How to Wipe Free Space on Your Windows PC Safely?

Did you know that when you delete files from your hard disc, the file is never truly erased and can most likely be restored using software like Stellar Data Recovery? This isn’t usually an issue because we use our computers every day; however, if you’re going to sell or donate your computer and don’t want your old data to be recovered, use the procedures below to delete the free space on your hard drive. The procedure is the same on Windows 7, 8, and 10, and it will work on all of them.

When you remove a file, what exactly happens?

The only thing that is deleted when you delete a file from your computer is its reference in the master file table. The file is still on your hard drive, but Windows is unaware of its location. This is because, as previously said, you’re just removing the indexes and linkages to the data and instructing Windows to overwrite that part of the hard drive.

As a result, data recovery software applications or the correct combination of abilities can recover the data until (and potentially after) it is written over. The tools, or a skilled hacker, can scan the hard drive for files and restore the linkages and indexes so that Windows can see them again. If you’re selling or disposing of a computer, make sure the open space on the hard drive is safely erased so the files can’t be recovered.

Today, we’ll demonstrate how to use the cypher command on the command line to encrypt the free space and ensure that no data can be recovered. We’ll also discuss various third-party data wiping software that accomplish the same goal.


Make sure you shutdown all programmes before running the cypher command to securely overwrite the free space on your hard disc. This guarantees that the maximum amount of open space is wiped safely.

Start entering “command prompt” into the Cortana or Search icons on the Taskbar. Then, under Best match, select Command Prompt.

  • At the prompt, type the following command and hit Enter.
  • Data that hasn’t been assigned to any files or directories is overwritten three times before being permanently deleted. If you’re overwriting a lot of open space, this can take a long time.

As Cipher cleanses the free space on your hard drive, it goes through the processes below.

  • The cypher command creates a new folder called EFSTMPWP on the C disc and then produces a file in that folder that contains only zeros. It will continue to expand until the hard drive is full.
  • Then cypher deletes that file and creates a second one that is repeatedly filled with the number 255 until the file gets large enough to occupy the hard drive’s free space.
  • Then, until your hard drive is full again, cypher deletes the second file, creates a third file, and fills it with random numbers.
  • Crypt returns you to the prompt after deleting the third file. To close the Command Prompt window, type exit at the prompt.

Cipher wiped over the vacant space (old files) on your hard drive three times to ensure that no one could ever scan your disk drive and retrieve the data you deleted.

If you keep an eye on your hard drive space while cypher works, you won’t be startled to see it fill up. As noted in the previous phases, this is normal, and space will be freed up again.


If you don’t want to use the command line, you can use CCleaner, a free programme that safely wipes the free space on your hard drive. CCleaner comes in two variants: free and paid. The free version has a capability that wipes your hard drive’s free space, so that should suffice.

Open CCleaner and choose Tools on the left pane after you’ve downloaded and installed or updated it. From the Wipe drop-down menu, select Free Space Only. If you pick Entire Drive, you will be erasing ALL of the files on your hard drive—unless that is what you want to do. You can utilise the Entire Drive option to wipe the entire drive if you’re getting rid of the PC. When making this decision, exercise extreme caution.

From the Security drop-down list, choose the overwriting technique you desire. For the most part, simple overwrite is enough. Select Advanced Overwrite if you want CCleaner to operate like the cypher command (3 passes). Then, under the Drives box, select the hard drive you want to safely wipe the free space on and click Wipe.

BitRaser File Eraser

BitRaser File Eraser is a do-it-yourself utility for permanently erasing sensitive files, web browser history, app & system traces, and deleted files from your computer and external storage media. Your personal information is protected with this technology from falling into the wrong hands.

The software has the ability to permanently wipe deleted files from discs and partitions. The application protects even your erased sensitive information from unwanted recovery using any software or technique by erasing the unused storage space left up after removing a file. The software allows you to schedule file wiping procedures and have them run at a specific time and date. You can erase files, folders, and traces on a regular basis, such as once a day, daily, weekly, or monthly, or at system startup.

The BitRaser File Eraser programme creates an erasure report that includes information on the erase process and results. The report guarantees that all of your sensitive files, folders, volumes, programme traces, internet browser history, saved passwords, and other information has been successfully deleted, providing you with peace of mind.

What technique do you use to completely delete the vacant space on your hard drive?   In the comments section below, please share your opinions and observations.