Before you start
- Administrator access
- An internet connection (for DISM)
Method 1 Run DISM, then SFC
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Step 1: Open an administrator Terminal
Right-click Start and choose Terminal (Admin). Click Yes on the prompt.
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Step 2: Run DISM
Paste the first command below and press Enter. It downloads clean copies of damaged components from Windows Update. The progress can pause at 20% or 62% for a while; that’s normal.
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Step 3: Run SFC
When DISM finishes, run sfc /scannow. It checks every protected system file and replaces broken ones.
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Step 4: Restart
Restart the PC, even if no problems were found.
DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow| Message | Meaning |
|---|---|
| Windows Resource Protection did not find any integrity violations | All system files are fine |
| …found corrupt files and successfully repaired them | Fixed; restart your PC |
| …found corrupt files but was unable to fix some of them | Run DISM again, restart, then run sfc /scannow again |
| …could not perform the requested operation | Run SFC from Safe Mode |
Method 2 Check the disk for errors too
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Step 1: Schedule a disk check
In the admin Terminal, run chkdsk C: /scan for a quick online scan, or chkdsk C: /f to fix errors at the next restart (type Y to confirm).
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Step 2: Restart
For /f, restart and let the check complete. It can take a while on large hard disks.
Troubleshooting
DISM says “The source files could not be found”
Check your internet connection and Windows Update. Or mount a Windows ISO of the same version and use DISM /Online /Cleanup-Image /RestoreHealth /Source:X:\sources\install.wim /LimitAccess (replace X with the mounted drive).
SFC keeps finding the same problems
Try an in-place repair: run setup.exe from a Windows ISO and choose to keep files and apps. This reinstalls Windows without deleting anything.
Frequently asked questions
Is sfc /scannow safe?
Yes. It only replaces Microsoft system files with correct versions. Your personal files aren’t touched.
How long does it take?
DISM: 5–20 minutes. SFC: 5–15 minutes. Longer on hard disks.
Do I need to run it regularly?
No. Only when you have crashes, errors or features that stopped working.
Summary
Open Terminal (Admin), run DISM /Online /Cleanup-Image /RestoreHealth and then sfc /scannow, and restart. Add chkdsk if you suspect disk errors.
