“Windows Resource Protection Could Not Perform the Requested Operation”: 7 Fixes

Applies to: Windows 11 and Windows 10, when sfc /scannow (System File Checker) ends with “Windows Resource Protection could not perform the requested operation.”

What the error means

Windows Resource Protection is the part of Windows that guards core system files. sfc /scannow asks it to check those files and replace damaged ones with clean copies from the component store (the C:\Windows\WinSxS folder).

This message means the scan couldn’t start or couldn’t finish. It doesn’t tell you your files are damaged, only that SFC was blocked. The usual causes are:

• A Windows update or repair is waiting for a restart.
• The Windows Modules Installer (TrustedInstaller) service is disabled.
• The component store that SFC copies clean files from is itself damaged.
• File system errors on the drive.
• Security software or another program locking system files.

Work through the fixes in order and run sfc /scannow again after each one.

Fix 1: Restart and run SFC as administrator

Updates that are waiting for a restart are the most common cause. Choose Start > Power > Restart (not Shut down, which can keep the old session with Fast Startup). If Windows offers Update and restart, use that.

Then press Win, type cmd, right-click Command Prompt and choose Run as administrator. Run:

sfc /scannow

Let it reach 100%. It can pause at some percentages for several minutes, which is normal.

Fix 2: Start the Windows Modules Installer service

SFC relies on the Windows Modules Installer service. If someone disabled it to stop updates, SFC fails. In an administrator Command Prompt, run:

sc config trustedinstaller start= demand
net start trustedinstaller

The space after start= is required. “The requested service has already been started” is fine. Then run sfc /scannow again.

You can also check it in Services (Win + R, services.msc): Windows Modules Installer should be set to Manual, not Disabled.

Fix 3: Repair the component store with DISM

SFC takes its clean copies from the component store. If that store is damaged, SFC can’t do its job. DISM checks and repairs the store, downloading good files from Windows Update. You need an internet connection. In an administrator Command Prompt:

DISM /Online /Cleanup-Image /ScanHealth
DISM /Online /Cleanup-Image /RestoreHealth

RestoreHealth can take 10 to 30 minutes and may sit at 20% or 62% for a while. When it finishes with “The restore operation completed successfully”, restart and run sfc /scannow again.

If DISM fails with 0x800f081f (source files could not be found), it couldn’t download the repair files. Fix 7 below works around that.

Fix 4: Check the disk with CHKDSK

File system errors can stop SFC from reading files. Start with an online scan, which doesn’t need a restart:

chkdsk C: /scan

If it reports errors, run the full repair. Windows can’t fix the drive it’s running from while it’s in use, so it asks to schedule the check for the next restart. Type Y and restart:

chkdsk C: /f

Use chkdsk C: /r instead if you suspect bad sectors. It reads the whole disk and can take hours on a large hard drive. Back up important files first if the drive is old or making noises.

Fix 5: Run SFC in Safe Mode

Safe Mode loads only basic drivers and services, so third-party antivirus and other tools can’t lock files during the scan.

1. Open Settings > System > Recovery (on Windows 10: Update & Security > Recovery).
2. Next to Advanced startup, select Restart now.
3. Choose Troubleshoot > Advanced options > Startup Settings > Restart.
4. Press 4 for Safe Mode (or 5 for Safe Mode with Networking).
5. Sign in, open Command Prompt as administrator and run sfc /scannow. Restart normally when it’s done.

If SFC works in Safe Mode but not normally, a program is interfering. Security suites are the usual suspect, so it’s worth a full scan with Microsoft Defender too. Our guide on how to scan for malware walks through that.

Fix 6: Run SFC offline from the recovery environment

Running SFC from outside Windows means nothing is in use, and no pending action can block it.

1. Go to Advanced startup > Restart now as in Fix 5, then choose Troubleshoot > Advanced options > Command Prompt.
2. Drive letters can be different here. Type dir C:\Windows. If you get “File Not Found”, try dir D:\Windows until you find the drive that holds Windows.
3. Run SFC against that drive (replace C: if your Windows drive has a different letter):

sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows

When it finishes, type exit and choose Continue to start Windows.

Fix 7: Repair Windows without losing files

If SFC and DISM still fail, reinstall Windows over itself. This replaces every system file and keeps your apps, files and settings.

• Windows 11: go to Settings > System > Recovery and select Reinstall now next to Fix problems using Windows Update.
• Windows 10 or 11 from an ISO: download the Windows ISO from Microsoft’s official download page, double-click it to mount it, run setup.exe, and on the “Choose what to keep” screen pick Keep personal files and apps.

Back up your important files before you start, as you would before any big change. A repair install takes about an hour and restarts the PC several times.

Other SFC messages and what they mean

Message	What it means
Windows Resource Protection did not find any integrity violations.	Your system files are fine. The problem you’re chasing is somewhere else.
Windows Resource Protection found corrupt files and successfully repaired them.	Fixed. Restart the PC.
Windows Resource Protection found corrupt files but was unable to fix some of them.	Run DISM RestoreHealth (Fix 3), restart and run SFC again.
Windows Resource Protection could not start the repair service.	The Windows Modules Installer service is disabled. See Fix 2.
There is a system repair pending which requires reboot to complete.	Restart and run SFC again. If it repeats, run SFC offline (Fix 6).
You must be an administrator running a console session.	Open Command Prompt with Run as administrator.

To see exactly which files SFC found and what it did, export the details to a text file on your desktop:

findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log >"%userprofile%\Desktop\sfcdetails.txt"

Frequently asked questions

Should I run DISM or SFC first?

If SFC fails or can’t repair files, run DISM first, then SFC. DISM fixes the store SFC copies clean files from, so running SFC after DISM gives it good sources to work with.

Is it safe to run SFC and DISM?

Yes. Both are built into Windows and only replace protected system files with Microsoft’s own copies. They don’t touch your documents, photos or installed apps.

Why does SFC get stuck at a certain percentage?

SFC checks thousands of files and some stages take longer, especially on hard drives. Leave it for at least 30 minutes before deciding it’s frozen.

Can this error cause crashes?

The SFC message itself is harmless, but the damage that stopped it can cause crashes and errors such as 0xc0000005 (application unable to start). Once SFC runs cleanly, check whether the original problem is gone.