Windows File System Checker Tool

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Before you beginSave open work and back up important files if you are experiencing crashes, disk errors, or possible data loss. Run commands only from an Administrator Command Prompt or Terminal.

1 Identify the issue

What are you trying to fix? Suspected corrupted or missing system files Blue screens or recurring crashes Slow performance, freezing, or hangs File errors, CRC errors, or disk warnings Something else or I am not sure

2 Run System File Checker (SFC)

SFC scans protected Windows system files and replaces damaged copies where possible.

sfc /scannow

What was the SFC result? No integrity violations were found Corrupt files were found and repaired Corrupt files were found but some could not be repaired SFC failed with an error I did not run SFC

3 Check and repair the Windows image with DISM

DISM repairs the Windows component store that SFC uses as its repair source.

DISM /Online /Cleanup-Image /CheckHealthDISM /Online /Cleanup-Image /ScanHealthDISM /Online /Cleanup-Image /RestoreHealth

Run the commands one at a time. After a successful RestoreHealth, run sfc /scannow again.

What was the DISM result? Component store was healthy DISM repaired corruption DISM found issues but could not repair them DISM failed with an error I did not run DISM

4 Check the drive with CHKDSK

CHKDSK checks the file system and drive for errors. It may need to run after a restart.

chkdsk C: /f /r

Replace C: if Windows is installed on another drive. The /r option can take a long time on large drives.

What was the CHKDSK result? No errors were found Errors were found and fixed Bad sectors or serious disk errors were reported CHKDSK failed or could not run I did not run CHKDSK

5 Assess the system after checks

How is Windows behaving now? The issue is improved or resolved No meaningful change It is worse, crashes often, or files may be at risk

Summary & Suggested Next Steps