DISM (Deployment Image Servicing and Management) repairs the Windows system image that System File Checker relies on. When SFC reports files it can’t fix, or Windows Update keeps failing, running DISM first and then SFC fixes most corruption without reinstalling Windows 11. You need an administrator account and, ideally, an internet connection.
Quick answer
Right-click Start, open Terminal (Admin), and run DISM /Online /Cleanup-Image /RestoreHealth. When it finishes, run sfc /scannow and restart.
Step 1: Open an administrator terminal
Right-click the Start button and choose Terminal (Admin), then select Yes. Command Prompt and PowerShell both work for these commands.
Step 2: Check and scan the image (optional)
| Command | What it does | Time |
|---|---|---|
DISM /Online /Cleanup-Image /CheckHealth |
Quickly reports whether corruption was already detected | Seconds |
DISM /Online /Cleanup-Image /ScanHealth |
Scans the image thoroughly without fixing anything | Several minutes |
DISM /Online /Cleanup-Image /RestoreHealth |
Scans and repairs, downloading clean files from Windows Update | 10 to 30 minutes or more |
You can skip straight to RestoreHealth; it includes the scan.
Step 3: Repair with RestoreHealth
- Run
DISM /Online /Cleanup-Image /RestoreHealth. - Wait. The progress bar often pauses at 20% or 62.3% for a long time; that’s normal.
- Look for “The restore operation completed successfully.”
Step 4: Run System File Checker
Run sfc /scannow in the same window. SFC now uses the repaired image to fix system files. Restart when it finishes. For details on reading SFC’s results, see running an SFC scan.
If DISM can’t download repair files
Errors such as 0x800f081f (“The source files could not be found”) mean DISM couldn’t get clean files from Windows Update. Use a Windows 11 ISO as the source instead:
- Download the Windows 11 ISO from Microsoft, matching your installed version and edition, and double-click it to mount it (note the drive letter, for example E:).
- Check that the folder E:\sources contains install.wim (or install.esd).
- Run
DISM /Online /Cleanup-Image /RestoreHealth /Source:wim:E:\sources\install.wim:1 /LimitAccess, changing the letter and file name to match. The number after the colon is the edition index.
Free up space with component cleanup
After updates, old component versions pile up in the WinSxS folder. DISM /Online /Cleanup-Image /StartComponentCleanup removes superseded ones safely. Don’t delete files from WinSxS by hand.
Read the DISM log
If a command fails, the details are in C:\Windows\Logs\DISM\dism.log. Search it for the error code shown on screen.
When DISM and SFC aren’t enough
- Run Startup Repair if Windows won’t boot.
- Use an in-place repair install from the Windows 11 ISO (run setup.exe and keep files and apps), which reinstalls Windows without losing your data. See repairing Windows 11 from USB.
- As a last resort, reset the PC.
Frequently asked questions
Is it safe to run DISM?
Yes. The scan and repair commands only fix Windows system files; they don’t touch your personal files or apps.
Should I run DISM or SFC first?
Run DISM RestoreHealth first, then SFC. That way SFC has a healthy source to copy from.
Does this work on Windows 10?
Yes, with the same commands. See using DISM to repair Windows 10.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.