We’ve seen these terms floating around forums and how-to articles for years when someone is explaining what to do with USB flash drives. Most people gloss over the definitions of Clean, Erase, and Format because the terms sound interchangeable or because they are not planning to perform the task being discussed.
The goal of this article is to clearly explain the differences between Clean, Erase, and Format so you can better understand what people mean when discussing USB flash drive maintenance and data removal.
All of the functions below can be performed on a Windows 10 system or newer. We’ll start with the simplest operation and work toward the more advanced ones.
Format
Formatting is what roughly 98% of Windows users rely on. This is the graphical option you see when you right-click a drive letter in Windows Explorer and select “Format.” But what does this function actually do?
Formatting is the least complicated option. It removes the file allocation table from the USB flash drive and creates a new one. Put simply, the operating system deletes the index that tells Windows where files are stored, making the drive appear empty.
The important detail is that the data itself still exists on the drive. It is no longer organized in a way that Windows can easily display, but the underlying information remains intact.
Using basic file-recovery tools, like the one we reviewed previously, it is often possible to recover most or all of the files that were on the drive.
The image below illustrates this concept. The light-gray area represents data that still exists on the flash memory but is no longer referenced by the file system. Recovery software scans this space to reconstruct files. Notice that the boot code area of the drive is untouched during a standard format.
If you’re wondering whether a flash drive should be formatted as FAT, FAT32, exFAT, or NTFS, we previously published a detailed comparison covering those file systems.
Clean
The Clean function goes a step further than formatting. It directly targets the Master Boot Record and partition information of the USB flash drive.
Running Clean removes the boot code and deletes all partitions. The partition data is what tells a computer how large the drive is and whether it can be used as a bootable device.
The Clean function is not available through the standard Windows graphical interface. It can only be accessed through the Windows command-line utility DiskPart.
The image below highlights the boot code area affected by the Clean command. While this portion of the drive is cleared, the actual data area remains intact, which is why Clean executes very quickly.
The most common reason to use Clean is troubleshooting. If a flash drive contains data but no longer behaves correctly when connected to a computer, clearing corrupted boot or partition information can sometimes restore functionality while preserving recoverable data.
To run Clean on a USB flash drive:
- Type diskpart into the Windows search bar and press Enter
- Type list disk and press Enter
- Identify which disk number corresponds to your USB flash drive
- Type select disk 1 (replace 1 with your USB’s disk number) and press Enter
- Type clean and press Enter
- DiskPart will confirm when the process is complete
After running Clean, the drive will appear as RAW and unreadable to Windows. To make it usable again, open Disk Management, locate the unallocated space, create a new simple volume, and follow the formatting wizard.
Clean All
The Clean All command is the most thorough option. Like Clean, it is only available through DiskPart, but it also writes zeros across the entire memory space of the flash drive.
This means all previous data is physically overwritten. Once Clean All is complete, file recovery is no longer possible.
For readers familiar with Department of Defense data-destruction methods, Clean All is conceptually similar to a single-pass overwrite. Traditional DoD methods repeat this process multiple times using different patterns.
Common reasons to use Clean All include securely handing a drive to another person, recycling a USB flash drive, or ensuring a virus is completely removed.
To run Clean All, follow the same DiskPart steps as Clean, but replace the final command with clean all. Because the entire memory space is overwritten, this process can take significant time depending on drive capacity.
This tutorial applies to Windows 7, Windows 8, and Windows 10 systems. Administrator privileges are required to use DiskPart’s Clean and Clean All commands.
This article was inspired by a forum discussion on TenForums.com.
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In the event your freight forwarder or delivery service tells you that an ECCN is needed to ship USB flash drives and is required to complete the Automated Export System (AES) or other documentation then please give them the above information and it should all work out.
ECCN stands for Export Control Classification Number. An ECCN is an alpha-numeric classification used in the Commerce Control List to identify items for export control purposes.
HS Code is the “Harmonized System” which is a 6-digit standardized numerical method of classifying traded products developed and maintained by the World Customs Organization. The Harmonized System system (HS) forms the basis of all countries’ tariff Schedule all over the world. Or it helps countries asses value to a product in a standardized way and by definitions all countries can agree and interpret.
