How to Erase Data from a USB Flash Drive….Permanently

So when you delete a load of files from a disk, they can still be recovered. You knew that……..right?

Whether it be your PC’s hard drive, and external hard drive, or even a USB flash drive, those files aren’t gone completely. Internal or external drives – both can have data recovered after you have deleted it.


If you want to send those bits and bytes into oblivion, so that no one can recover anything, you will have to take a few extra steps.


So the first option is to get an app to do the work for you. There are plenty of programs and downloads out there that you can choose from, but Eraser is a good one – and it’s free!

Step 1 is to download and install the app, following the usual procedures. Once installed, run it.

Step 2 is to create a new task. Right-click anywhere in the white area of the main windows and click on NEW TASK. (Or press CTRL+N on your keyboard)eraser1

You will get a pop-up box where you can set up the main details for your task. Type a name/description for your task, and choose when to run (Use the Schedule tab to specify a specific date/time)

Click ADD DATA and choose the flash drive that you want to wipe.

**NB!!! You need to make sure that you choose the right drive – whichever drive you choose WILL BE WIPED OUT!

Once you have selected the drive, click OK to return to the main screen.


Next, you need to choose your erasure method. There are different algorithms available, but using the Schneier 7 Pass Method should suffice. The more passes you make, the longer the erasing process will take, especially on today’s large capacity drives.

7 passes is a fair trade off between speed and efficiency.

Click on Settings and make your choice, and click SAVE SETTINGS when you are done.


Return to the main screen, and to run your new erasure task, right click on it, and click RUN NOW.


Microsoft Windows has a load of built in command prompt tools, and for data deletion, there is CIPHER.

  1. Open an elevated command prompt. Do this by clicking the start button, typing CMD in the search box, right-clicking on the cmd.exe app that pops up, and choose RUN AS ADMINISTRATOR
  2. Type cipher /? to see a full list of switches and descriptions that can be used with cipher
  3. If you scroll through the list of switches, you will see /W, which stands for WIPE. This option will read whichever drive you select, and permanently overwrite all data bits that are masked as unused
  4. Run Cipher on your Flash drive:

Flash drives have built in “wear-leveling” algorithms that try to evenly distribute data across all storage cells in order to prolong the life of the flash drive. Your OS cannot override that. (Cipher was developed in the days of hard drives) As such, you can never be 100% sure that Cipher will clean the drive completely. You can run Cipher more than once to try and combat this flaw. Make sure to format the flash drive before you run Cipher. To run Cipher, type the following at an elevated command prompt:

C:\Windows\System32\>cipher /w X:SANDISK

(Replace X:\SANDISK with your flash drive letter and name)

Again, make 100% sure that you have the correct drive letter here – a mistake here could cost you.


A last resort is to physically destroy the drive in question. Get a hammer (and some safety goggles!), and go crazy…


Thanks go to for the great advice.


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