Repair Windows with SFC and DISM

What you will achieve

Repair corrupted Windows system files using built-in tools before resorting to a clean install.

When to use SFC and DISM

• Windows Update fails repeatedly with corruption errors.
• System apps crash or missing components behave oddly.
• sfc /scannow reports it could not repair some files.

1) Run SFC (System File Checker)

1. Open Terminal (Admin) or Command Prompt as administrator.
2. Run:

sfc /scannow

Allow 15–30 minutes. Do not close the window. Reboot if repairs are reported.

2) Run DISM if SFC cannot fix everything

Deployment Image Servicing and Management repairs the component store Windows uses for repairs:

DISM /Online /Cleanup-Image /RestoreHealth

Requires internet to pull repair files from Windows Update. Run sfc /scannow again afterward.

3) Check logs if problems remain

findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log

Advanced users can inspect CBS.log for files SFC could not repair — often points to optional feature reinstalls.

4) If corruption is deep

In-place upgrade repair (setup.exe from ISO while running Windows) or a clean install may be faster than endless DISM loops on badly damaged systems.

Verify

• SFC ends with “Windows Resource Protection did not find any integrity violations” or repaired successfully.
• Previously failing updates or apps work again.