Erase USB or Clean USB or Format USB?

We’ve seen these terms floating around in forums and How To’s for years when someone is explaining what to do with USB flash drives. I think most people glaze over the definitions of Clean, Erase and Format simply because they believe the terms are interchangeable, or they aren’t planning on doing the task mentioned in the post.

I hope the following information will clear up some terms and definitions so we can all better understand what people are talking about when passing along information about flash drives and the Clean, Erase and Format function.

All of these functions can be performed in your Windows 10 computer, or higher. I will start with the least complicated definition and task, and move along from there.

This function is what 98% of Windows computer operators will use. This is the graphical interface inside Windows when you right click a drive letter and ask the operating system to format the drive. What is this function really doing?

Format is the least complicated of the tasks, and this function is removing the File Allocation Table of the USB and creating a new one. Said a simpler way… this function takes away the list of files sitting on the drive so it then appears blank with no data.

It’s important to note, the files are still on the drive, just not listed in an easy, organized manor which you can see through windows explorer (clicking on the drive letter to see the list of files).

Using the most basic file recovery software tools, like the one we wrote about several months back, you can recover all the files sitting on the drive.

Maybe a picture will help. Looking at the image below you can see the “data” is light grey. Meaning the data is still there, just not easily accessible. This data is what recovery software will look for, find, and list back on your drive. Also notice the boot code of the USB (if you want to load an operating system on your USB stick) isn’t touched either.

You might have questions if a USB flash drive should be formatted as FAT, FAT32, exFAT or NTFS and we did a great post about that a bit earlier as well.

Clean

The Clean function is a bit more in-depth than the format function. This function applies directly to the Master Boot Record (MBR) or boot code mentioned just above.

The Clean function will clear out boot code and will remove any partition on the flash drive. The partition of a flash drive is the information which tells a host computer how big the drive is, and if the partition should be bootable in the event you are trying to start the computer from a flash drive.

The Clean function is not accessible through the GUI of Windows, for example you cannot right click on a drive letter and find the Clean function. The Clean function is only accessible through the Windows utility called DiskPart.

Looking at the image below, you will see we framed the boot code in red, yet all the data is still there. The area in red is what the Clean function will address. The Clean function, or process, is very quick because it only deals with a small portion of the drive.

Before moving along to the instructions on how to Clean your USB flash drive, let me address the most common reason why you’d want to Clean your USB in the first place. I would imagine the most common reason is that a user has a flash drive with data on it, but the device isn’t working properly. The goal would be to get the USB drive working again, and then try to salvage whatever data is on the drive.

The Clean function will clean the drive of any possible code which is causing the USB not to work as expected when connected to the host computer. Using the clean function could restore that important code, yet still leave the data on the drive to be recovered.

To run Clean on your USB stick, do the following:

• Type diskpart into the search bar of Windows and click Enter
• Type list disk and click Enter
• From the list given identify which number is your flash drive
• Type select disk 1 (1 represents your USB drive) and click Enter
• Type clean and click Enter
• DiskPart will display when the process is done

Once the Clean process is finished, we must make the drive readable by Windows because this current state is a RAW drive. Meaning a drive without a partition table telling the operating system how much storage space is on the USB flash drive (and file structure and other bits of info)

Right click the Windows start icon in the bottom left of your screen, and from the list provided select Disk Management

A screen will pop up and display all the connected storage devices. You will notice the drive letter associated with your USB flash drive is “unallocated” space. Said another way, Windows can see the memory space, but doesn’t know how to interact with it.

Select the drive letter of unallocated space and right click. A window will display with options and you will want to select Create Simple Volume. From this point forward, use the Wizard and work through the steps to format your drive.

At this point, if you are trying to recover data files from your drive, the data recovery software should now see the drive and try to perform it’s recovery process.

Clean All

The Clean All function will really clean your drive from bow to stern. Like the Clean function, this process is only accessible through DiskPart in Windows. The Clean All function will clear the Master Boot Record (MBR) or boot code along with the partition table, and in addition, will write zero’s to all the memory space of the device.

That last bit is most important. The Clean All function will write over any zero’s and one’s which represent your data with all zero’s.

Take a look at the picture below. Both the boot code area and data area are framed in red, meaning a change. See all zeros in grey after the Clean All function is completed. This means any previous data on the drive was overwritten.

For those of you who wonder what D.o.D. (Department of Defense) Erase function is, it would be this function, but ran at least three times on the device. The first pass is all zeros. The second pass is all ones. The third pass is all zeros again. The exact process could change a little, but that is the overall concept

Why would anyone want to Clean All to a USB flash drive?

Below are three of the most common reasons why someone would want to Clean All a USB stick:

• Giving device to another indvidual and insure no data
• Recycling the USB drive and want to insure no data
• A virus is found on the device and you want to make absolute sure the virus is removed

To run Clean All on your USB stick, do the following:

• Type diskpart into the search bar of Windows and click Enter
• Type list disk and click Enter
• From the list given identify which number is your flash drive
• Type select disk 1 (1 represents your USB drive) and click Enter
• Type clean all and click Enter
• DiskPart will display when the process is done. Note: Since zeros are being written to the entire memory space this could take a while. The time duration will depend on how many GBs are on the flash drive.

Once the Clean All process is finished, we must make the drive readable by Windows because this current state is a RAW drive.

Right click the Windows start icon in the bottom left of your screen, and from the list provided select Disk Management

A screen will pop up and display all the connected storage devices. You will notice the drive letter associated with your USB flash drive is “unallocated” space.

Select the drive letter of unallocated space and right click. A window will display with options and you will want to select Create Simple Volume. From this point forward, use the Wizard and work through the steps to format your drive.

This tutorial is for use with DiskPart in Windows 7, Windows 8, and Windows 10. You must be signed in as an administrator to “Clean” or “Clean All” a flash drive, or any drive connected.

This post was inspired by a short forum post found at TenForums.com