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sfc /scannow Explained: What It Does and How to Read the Results

Beginner Command Prompt Fixes Applies to: Windows 7, Windows 10, Windows 11

The most common Windows repair command — here's what it actually checks and what its output means.

Before you start: save any open work and note down what you were doing when the problem started — that context helps if you need to search further or ask for help.
  1. Open Command Prompt as administrator (see our guide on running it as admin), then type sfc /scannow and press Enter.
  2. Let it run fully — it scans every protected system file against a known-good copy, which typically takes 10-20 minutes depending on your drive.
  3. If it reports "Windows Resource Protection did not find any integrity violations," your system files are fine and the problem you're troubleshooting lies elsewhere.
  4. If it reports it found and successfully repaired corrupt files, that's a good sign — restart and see if your original problem is resolved.
  5. For more detail than the on-screen summary gives you, extract the specific results from SFC's own log file: run findstr /c:"[SR]" %windir%\logs\cbs\cbs.log >"%userprofile%\Desktop\sfcdetails.txt" in the same admin Command Prompt, then open sfcdetails.txt on your desktop — it lists exactly which files were checked, found corrupt, and repaired, rather than just the pass/fail summary.
  6. If it reports finding corrupt files it "was unable to fix," run DISM /Online /Cleanup-Image /RestoreHealth first, then run sfc /scannow again — DISM repairs the underlying image sfc relies on.
  7. If instead SFC fails to even complete, showing "Windows Resource Protection could not perform the requested operation," that's a different problem entirely — SFC itself couldn't run, not a report about your files. See our dedicated page on that exact error for the specific fix.
Mentioned above: "Windows Resource Protection Could Not Perform the Requested Operation"
Still not fixed? Send us the details and we'll help you dig further, or browse related guides in Command Prompt Fixes.

Frequently Asked Questions

How long does sfc /scannow take?
Typically 10-15 minutes, though it can take longer on an older or slower drive. Don't interrupt it once it's running — closing the window or restarting mid-scan can leave the process incomplete.
Is sfc /scannow safe to run even if nothing seems wrong?
Yes, it's a genuine, official Microsoft tool that only checks and repairs — it doesn't remove your files or programs. Running it as a precaution or diagnostic step carries no real risk.
Do I need to run this as Administrator?
Yes — sfc /scannow needs to be run from an elevated (Administrator) Command Prompt or PowerShell window. Right-click the Start button or search result and choose "Run as administrator"; running it from a regular Command Prompt will fail with an access-denied message.

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