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Formatted the wrong drive making a bootable USB? Read this

November 7, 2026

Making a Windows installer or a Linux boot stick should take ten minutes. Then you look at the drive letters and realise that the drive Rufus, the Media Creation Tool or balenaEtcher has just “prepared” was not the empty USB stick at all, but the external drive with your photos, or the memory stick with your work files. It is a very common mistake, and how much can be recovered depends on which tool you used, what kind of drive it was and what you do next.

Stop using the drive straight away

Before anything else:

  • Cancel the process if it is still running, then safely remove the drive.
  • Do not let the tool finish “just to see”.
  • Do not reformat the drive back to how it was. A second format adds another layer of damage.
  • Do not copy anything onto it, and do not install recovery software onto it.
  • Label the drive and put it somewhere safe.

Every extra write lands on the same area where your file system used to be, so the less the drive is used, the better your chances.

What each tool actually does to the drive

Rufus

Rufus creates a new partition table on the selected drive, formats a new partition (usually FAT32 or NTFS) and then copies the contents of the ISO onto it. For a Windows image that is several gigabytes of new data written at the start of the drive. Rufus hides USB hard drives by default, so if an external hard drive was wiped, the option to list USB hard drives had probably been switched on at some point.

Windows Media Creation Tool

The Media Creation Tool warns that everything on the drive will be deleted, formats it and then downloads and writes the Windows installation files. As with Rufus, the start of the drive is rewritten and several gigabytes of new files are added.

balenaEtcher and similar image writers

Etcher writes the image file sector by sector from the very start of the drive. Everything in the area covered by the image is replaced. Anything beyond the end of the image is not touched by the write itself, but the original partition table and file system information at the start of the drive are gone.

What that means for your files

The information that tells a computer where each file lives, and what it is called, is usually kept near the beginning of the drive. That is exactly the area these tools overwrite. As a result:

  • files stored in the part of the drive that was overwritten are generally lost
  • files stored further into the drive often still exist, but without their original folder structure
  • some file names may be lost, so recovered files can come back with generic names
  • photos, videos and documents can often still be identified by their content

So a 2 TB external drive that had a few gigabytes written to it still holds most of its original data. A 16 GB memory stick that had a Windows image written to it may have had most of its contents replaced.

Hard drive, USB stick or SSD?

External hard drives are the best case. Data that was not physically overwritten stays where it was until something new is written over it.

USB sticks and memory cards are more variable. The controller inside decides where data is physically stored, and on smaller sticks the image may cover much of the capacity. Sticks that also have a fault, such as disconnecting or showing the wrong size, need extra care. Our SanDisk data recovery page covers the flash drives we see most often.

SSDs, including many portable SSDs, are the hardest case. Formatting can cause the SSD to be told that the old data is no longer needed (TRIM), and the drive may then clear it internally. If the wiped drive was an SSD, act quickly and do not keep it plugged in.

What not to try

  • Running several recovery programs one after another. Each one can write logs or recovered files back to the wrong place if you are not careful.
  • Recovering files onto the same drive. Always save recovered data to a different disk.
  • Using “partition repair” tools that write a new partition table. If they guess wrongly, they make the next attempt harder.
  • Running CHKDSK. It may “fix” the new file system and remove traces of the old one.

How a lab approaches it

We start by making a complete sector-by-sector copy of the drive and work only on that copy. We then look for surviving traces of the original file system beyond the overwritten area, and search the whole copy for file signatures to rebuild photos, videos and documents. You get a list of what was found before you decide anything. If the drive was in a Windows PC or laptop, our Windows data recovery page explains the wider service.

Get a free assessment

If you have formatted the wrong drive while making a boot stick, unplug it and leave it alone. Call Data Retrieval on 020 7064 4996 or request a quote online. The assessment is free and there is no obligation.