What should I do when files on a USB drive appear corrupted?

First, stop using the drive as a place to store anything. Don’t copy files onto it, and don’t format it or accept a prompt to repair it yet. Microsoft recommends minimizing or avoiding use of a storage device when trying to improve the chance of recovering lost files. [S1]

Write down the exact message, what you were doing when it appeared, and which files or folders you need. If the drive contains irreplaceable work, pause before experimenting and consider asking a qualified data-recovery professional about options. That is a cautious choice, not a promise that recovery is possible.

If the files matter, don’t treat a repair prompt as the first recovery step. The supplied Microsoft guidance recommends minimizing use to improve recovery chances, and it describes Windows File Recovery as a tool that attempts file recovery—not a general fix for every kind of corruption. [S1] Since the prompt’s effect on your particular drive is not established here, avoid approving changes until you have chosen a recovery plan.

Keep a note of what the computer displays so you can refer to it when deciding what to do next.

One option is Windows File Recovery, which Microsoft says can attempt recovery from external and USB devices. The recovered files must be saved to a different drive, not the affected USB drive. The tool’s available modes depend on file-system and other conditions, and Microsoft does not present it as a guarantee or a universal repair. [S1]

Before trying it, check that you have another drive with room for the recovered files. If you’re unsure which mode or steps apply, consult Microsoft’s instructions rather than guessing. The supplied information does not establish whether your particular files are recoverable or which mode would suit your drive.

Use the value of the files and your comfort with the next steps as the decision points. For example, assume the drive holds a replaceable copy of class notes and you have another drive: you might review Microsoft’s recovery instructions and, if you proceed, save any recovered files elsewhere. If it holds the only copy of important work and you don’t want to risk further changes, stop using it and ask a qualified professional what options they offer.

A simple record to prepare is:

1. Drive label or description: [your label]
2. Error shown: [copy the exact wording]
3. Files needed most: [names or folders]
4. What happened just before the error: [brief notes]
5. Steps already tried: [list, or “none”]

This is an organizing aid, not a recovery diagnosis.

In Windows, use Safely Remove Hardware and wait for the “Safe To Remove Hardware” notification before disconnecting the USB drive. Microsoft presents this as a step for safely removing hardware; it does not diagnose or repair existing corruption. [S2]

For now, keep the affected drive unused while you decide on recovery. If you use Windows File Recovery, save recovered files to a separate drive. Keep the original error and your notes until you know whether you have the files you need.