Symptoms
- Notification says a drive needs to be checked/scanned for errors
- Sometimes accompanied by files becoming inaccessible or showing as corrupted
- May happen with an internal drive or specifically with an external/USB drive
- Prompt may reappear repeatedly even after running the check
Likely causes
- CommonFile system errors from an improper disconnection or shutdownRemoving a USB drive without safely ejecting it, or an improper PC shutdown, is a very common trigger.
- CommonDeveloping bad sectors on the drivePhysical wear can cause file system inconsistencies that trigger this warning.
- PossibleDrive formatted with a file system Windows flags more readily (like exFAT on some external drives)Certain file systems trigger these checks more proactively than others.
- PossibleFailing drive controller or connection issueAn unstable connection can cause read/write errors that look like file system corruption.
- Less commonMalware or improper software interaction with the driveSome software can cause file system inconsistencies through improper access patterns.
What to do
- Right-click the drive in File Explorer, choose Properties, go to the Tools tab, and click 'Check' under Error checking to run a scan.
- Let the scan run to completion, allowing it to fix any errors it finds, and note whether it reports needing a restart to complete (common for the drive Windows is installed on).
- For external drives, always use the 'Safely Remove Hardware' option before physically disconnecting them going forward, to prevent recurring file system errors.
- If the same external drive keeps triggering this warning even with safe removal, back up its data and consider reformatting it fresh.
- Run 'chkdsk [drive letter]: /f /r' from an administrator Command Prompt for a more thorough scan and repair, especially if the graphical tool doesn't fully resolve it.
- If errors keep recurring on an external drive despite reformatting, treat it as a sign of physical drive wear and plan to replace it, keeping backups elsewhere.
- If it's your main internal drive and errors recur frequently, monitor drive health using a tool that reads the drive's own S.M.A.R.T. status, and back up important files as a precaution.
Tools and parts
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When to call a pro
If disk checks keep finding and fixing the same errors repeatedly, or S.M.A.R.T. status shows warnings, a technician can assess whether the drive is failing and needs replacement.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.