I unpacked a brand-new 256GB SanDisk Ultra USB flash drive and connected it for the first time. It contained a few default files, but I skipped the included encryption software because I wanted to transfer files normally. I used cut and paste to move important files from my computer to the drive. Partway through the transfer, Windows displayed an error and the USB disconnected. After reconnecting it, the drive appeared briefly and disappeared again. Windows later offered to repair it, but the repair failed, and now the drive is not detected at all. The files are no longer in their original location or the Recycle Bin, and they never appeared on the USB drive. What recovery options should I try, and is the flash drive possibly defective or counterfeit?
4 Answers
A failed USB controller can make the drive disappear completely, so software repair may not help. If the missing files are irreplaceable and are not available elsewhere, avoid opening or repeatedly reconnecting the USB and use a professional lab. In this case, the files were ultimately recovered from another copy on the owner's phone, but the flash drive itself remained unusable.
Stop using the affected computer drive for anything unnecessary so deleted data is not overwritten. Check other locations first, such as cloud storage, phone backups, recent file versions, or temporary folders. If the files are important, make a sector-by-sector image of the computer drive and recover from that image with reputable data-recovery software—or contact a professional recovery service. Do not keep retrying Windows repair on the failed USB drive.
Using copy instead of cut would not have prevented the USB from failing, but it would have left the originals on the computer. A safer workflow is to copy the files, verify that they open correctly on the destination, and only then delete the originals. Important files should also exist in at least two separate locations.
The flash drive may simply be defective, but counterfeit high-capacity drives are also common. Some report a fake capacity and start corrupting or losing data once the real storage limit is reached. If the drive is detected again, test it with a full-capacity verification tool. Since it is new, document the symptoms and return or warranty-replace it rather than trusting it with data.
Fortunately, I found another copy of the files on my phone, so I was able to recover them. The USB drive still is not detected and I plan to return it.