Fix SFC: WRP Could Not Perform Operation

Understanding System File Checker (SFC) and WRP Errors

What is System File Checker (SFC)?

• Purpose: Scans and repairs corrupted Windows system files
• Command: sfc /scannow (most common usage)
• How it works: Compares current system files against cached copies in C:\Windows\WinSxS (component store)
• What it fixes: Missing DLLs, corrupted EXE files, damaged system drivers, registry inconsistencies
• Scan time: 20-60 minutes depending on system

What is Windows Resource Protection (WRP)?

• WRP: Windows security feature that protects critical system files from unauthorized modification
• Protected files: System32 files, drivers, registry keys, critical Windows components
• SFC uses WRP: SFC operates through WRP to safely repair protected files
• WRP errors: Indicate SFC cannot interact with Windows Resource Protection layer

Common SFC Error Messages and Meanings:

"Windows Resource Protection could not perform the requested operation"

• Meaning: SFC cannot start or access necessary resources
• Causes: Running processes locking files, insufficient permissions, corrupted CBS store
• When it appears: Often immediately at scan start or early percentage

"Windows Resource Protection found corrupt files but was unable to fix some of them"

• Meaning: SFC detected corruption but repair failed
• Causes: Files locked by running processes, corrupted CBS store, disk errors
• When it appears: After 100% scan completion

"Windows Resource Protection could not start the repair service"

• Meaning: Windows Modules Installer service not running or corrupted
• Causes: Service disabled, service crashed, Group Policy restrictions
• When it appears: Immediately when starting SFC

"There is a system repair pending which requires reboot to complete"

• Meaning: Previous SFC scan or Windows Update requires restart before new scan
• Causes: Pending file renames or component registrations
• When it appears: At SFC start

Method 1: Run DISM to Repair Component Store First

DISM (Deployment Image Servicing and Management) repairs the Windows component store that SFC relies on. Always run DISM before SFC if SFC fails.

1. Open Command Prompt as Administrator:
   • Press Windows + X → Terminal (Admin) or Command Prompt (Admin)
   • Or search "cmd" → Right-click → Run as administrator
2. Check component store health:
3. DISM /Online /Cleanup-Image /CheckHealth
4. Quick check (30 seconds)—reports if corruption detected
5. Scan for corruption (thorough):
6. DISM /Online /Cleanup-Image /ScanHealth
7. Deeper scan (5-10 minutes)—verifies component store integrity
8. Repair component store:
9. DISM /Online /Cleanup-Image /RestoreHealth
10. This is the key command—downloads and repairs corrupted components
11. Takes 10-30 minutes, progress percentage may seem stuck—be patient
12. If successful: "The operation completed successfully"
13. If error 0x800f081f (source files not found), see Method 2 for offline repair
14. After DISM completes successfully, run SFC:
15. sfc /scannow
16. SFC should now work without "could not perform" error

Understanding DISM vs SFC:

• DISM: Repairs the Windows image and component store (the "source" of repair files)
• SFC: Uses the component store to repair actual system files
• Relationship: If component store is corrupted, SFC cannot get clean files to replace corrupted ones
• Best practice: Always run DISM before SFC when troubleshooting

Method 2: Run DISM with External Source (If DISM Fails)

If DISM reports error 0x800f081f or cannot download repair files, use Windows installation media as repair source.

1. Obtain Windows installation media:
   • Download Windows 11/10 ISO from Microsoft
   • Or use existing Windows installation USB
2. Mount ISO (if using ISO file):
   • Right-click ISO file → Mount
   • Note drive letter (e.g., E:)
3. Identify install.wim or install.esd location:
   • Navigate to mounted ISO: E:\sources\
   • Look for install.wim or install.esd
4. Run DISM with source:
5. For install.wim:
   • DISM /Online /Cleanup-Image /RestoreHealth /Source:E:\sources\install.wim:1 /LimitAccess
   • Replace E: with your ISO drive letter
   • :1 specifies Windows edition index (usually 1 for Home, 4 for Pro—check with DISM /Get-WimInfo /WimFile:E:\sources\install.wim)
6. For install.esd:
   • DISM /Online /Cleanup-Image /RestoreHealth /Source:E:\sources\install.esd:1 /LimitAccess
7. /LimitAccess prevents DISM from using Windows Update (uses only your source)
8. Wait for completion (10-40 minutes)
9. After DISM succeeds, unmount ISO
10. Run SFC: sfc /scannow

Method 3: Run SFC in Safe Mode

Safe Mode loads minimal drivers and services, preventing processes from locking files that SFC needs to repair. Most effective method for "files locked" issues.

Boot into Safe Mode:

Method A: From Windows (if bootable):

1. Press Windows + I → System → Recovery
2. Under "Advanced startup," click Restart now
3. PC restarts to blue recovery menu
4. Click Troubleshoot → Advanced options → Startup Settings → Restart
5. After restart, press 4 or F4 for Safe Mode
6. Or press 5 or F5 for Safe Mode with Networking (allows internet access)

Method B: Force Safe Mode (if Windows unstable):

1. Force shutdown PC by holding power button 10 seconds
2. Turn on PC
3. When Windows logo appears, immediately force shutdown again
4. Repeat 2-3 times
5. Windows enters Automatic Repair
6. Click Advanced options → Troubleshoot → Advanced options → Startup Settings → Restart
7. Press 4 for Safe Mode

Run SFC in Safe Mode:

1. Once in Safe Mode, open Command Prompt as Administrator
2. Run: sfc /scannow
3. Wait for 100% completion (20-60 minutes)
4. Check results:
   • "Windows Resource Protection did not find any integrity violations" → No corruption found
   • "Windows Resource Protection found corrupt files and successfully repaired them" → Fixed!
   • "Windows Resource Protection found corrupt files but was unable to fix some of them" → Continue to Method 4
5. Restart computer to normal Windows

Why Safe Mode works: Third-party services, startup programs, and non-essential Windows components don't load, so files aren't locked by background processes.

Method 4: Run SFC Offline Scan (Windows Installation USB)

Offline SFC scans Windows installation from outside the OS, ensuring no files are locked. Most thorough method for severe corruption.

1. Boot from Windows 11/10 installation USB
2. On "Install now" screen, press Shift + F10 (opens Command Prompt)
3. Identify drive letters:
   • Type: diskpart
   • Type: list volume
   • Identify volumes:
     • Windows partition: Usually largest, labeled "Windows" or no label (e.g., D:)
     • EFI System Partition: ~100-500MB, FAT32 (e.g., C:)
     • Boot partition: ~100MB if separate (legacy systems)
   • Type: exit to leave diskpart
4. Run offline SFC:
5. sfc /scannow /offbootdir=C:\ /offwindir=D:\Windows
   • /offbootdir=C:\ → Boot partition (usually EFI partition, might be same as Windows partition)
   • /offwindir=D:\Windows → Windows installation folder (replace D: with your Windows drive letter)
   • If unsure, try: sfc /scannow /offbootdir=D:\ /offwindir=D:\Windows (both same drive)
6. SFC scans offline Windows installation (20-60 minutes)
7. After completion, type: exit
8. Remove USB, restart computer
9. Windows should boot with repaired files

Troubleshooting Offline SFC:

"Could not open the offline boot directory"

• Wrong drive letter for /offbootdir—try different letter or same as /offwindir

"Could not open the offline Windows directory"

• Wrong drive letter for Windows—verify with dir D:\ (should show Windows folder)

Method 5: Restart Windows Modules Installer Service

SFC requires Windows Modules Installer (TrustedInstaller) service. If service is stopped or corrupted, SFC fails immediately.

1. Press Windows + R, type services.msc, press Enter
2. Scroll to Windows Modules Installer service
3. Check Status column:
   • If "Running" → Right-click → Restart
   • If blank (stopped) → Right-click → Start
4. Right-click Windows Modules Installer → Properties
5. Set Startup type to Manual (default for this service)
6. Click Apply → OK
7. Close Services window
8. Open Command Prompt as Admin
9. Run: sfc /scannow

If Service Won't Start (Error 5 or 1058):

Reset service permissions:

1. Open Command Prompt as Administrator
2. Run: sc config trustedinstaller start= demand (space after start= is required)
3. Run: net start trustedinstaller
4. If still fails, service may be corrupted—continue to Method 6

Method 6: Check and Repair Disk Errors (CHKDSK)

Disk errors and bad sectors prevent SFC from writing repaired files. CHKDSK repairs disk problems before running SFC.

1. Open Command Prompt as Administrator
2. Run: chkdsk C: /f /r
   • C: System drive (replace if Windows on different drive)
   • /f: Fixes errors
   • /r: Locates bad sectors and recovers readable information
3. Message appears: "Chkdsk cannot run because volume is in use. Schedule scan at next restart?"
4. Type Y and press Enter
5. Restart computer
6. CHKDSK runs before Windows loads (20 minutes to 5 hours depending on disk size and errors)
7. Do not interrupt CHKDSK—let it complete all 5 stages
8. After CHKDSK finishes, Windows boots normally
9. Run DISM: DISM /Online /Cleanup-Image /RestoreHealth
10. Then run SFC: sfc /scannow

Check CHKDSK Results:

1. If CHKDSK found and fixed errors, they're logged
2. View CHKDSK log:
   • Press Windows + X → Event Viewer
   • Expand Windows Logs → Application
   • Look for "Chkdsk" source entries
   • Double-click to view details

Method 7: Manually Replace Corrupted System Files

If SFC identifies specific corrupted files but can't repair them, manually replace from known-good source (another PC or installation media).

Find Which Files Are Corrupted:

1. After SFC scan completes, check SFC log:
2. Run: findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log > "%userprofile%\Desktop\sfcdetails.txt"
3. This creates sfcdetails.txt on your Desktop
4. Open sfcdetails.txt with Notepad
5. Look for lines saying:
   • "Cannot repair member file" → File that SFC couldn't fix
   • File path shown (e.g., C:\Windows\System32\example.dll)
6. Note the corrupted file names and paths

Manually Replace Corrupted Files:

1. Obtain clean copy of corrupted file:
   • From another PC with same Windows version
   • From Windows installation media (mount ISO, extract from install.wim)
   • From Windows\WinSxS folder (search for filename)
2. Take ownership of corrupted file:
   • Right-click corrupted file → Properties → Security → Advanced
   • Click Change next to Owner
   • Type Administrators, click Check Names → OK
   • Check Replace owner on subcontainers and objects
   • Click Apply → OK
3. Grant full control permissions:
   • Properties → Security → Edit
   • Select Administrators group
   • Check Full Control
   • Click Apply → OK
4. Replace file:
   • Rename corrupted file (add .old extension as backup)
   • Copy clean file to same location
   • Restart computer
5. Run SFC again to verify: sfc /scannow

⚠️ Caution: Only replace files explicitly identified by SFC log. Replacing wrong files can cause system instability.

Additional Troubleshooting

Temporarily Disable Antivirus:

Antivirus can interfere with SFC by protecting system files from modification:

1. Disable real-time protection in your antivirus (Norton, McAfee, Avast, Kaspersky, etc.)
2. Run SFC: sfc /scannow
3. Re-enable antivirus after SFC completes

Clear Windows Update Cache:

Corrupted Windows Update cache can cause CBS store corruption:

1. Open Command Prompt as Admin
2. Stop Windows Update service: net stop wuauserv
3. Stop Background Intelligent Transfer Service: net stop bits
4. Navigate to update cache: cd %windir%\SoftwareDistribution
5. Rename folder: ren Download Download.old
6. Restart services:
   • net start wuauserv
   • net start bits
7. Run DISM: DISM /Online /Cleanup-Image /RestoreHealth
8. Run SFC: sfc /scannow

Perform In-Place Upgrade (Last Resort):

If all methods fail, in-place upgrade reinstalls Windows while keeping files and apps:

1. Download Windows 11/10 ISO from Microsoft
2. Mount ISO (double-click or right-click → Mount)
3. Open mounted drive, run setup.exe
4. Choose Keep personal files and apps
5. Follow wizard—Windows reinstalls (1-2 hours)
6. After completion, system files are fresh and SFC should work

Frequently Asked Questions

Q: SFC says "Windows Resource Protection could not perform requested operation" immediately when I start it. What's wrong?

A: Immediate failure indicates Windows Modules Installer service issue or permission problem: (1) Verify Windows Modules Installer service is running—open services.msc, find "Windows Modules Installer," ensure Status is "Running" or start it; if grayed out, set Startup type to "Manual" first (Method 5), (2) Run Command Prompt as Administrator—right-click CMD → "Run as administrator" is crucial; running as standard user causes this error, (3) Check for pending restarts—message "system repair pending which requires reboot" means previous Windows Update or repair needs restart before SFC can run; restart PC and try again, (4) Run DISM first to repair component store—DISM /Online /Cleanup-Image /RestoreHealth; corrupted CBS store prevents SFC initialization (Method 1). If none work, boot Safe Mode and try SFC there (Method 3)—Safe Mode bypasses many permission and service issues.

Q: SFC completed 100% but says "found corrupt files but was unable to fix some of them." How do I fix those remaining files?

A: SFC detecting but not repairing corruption means files are locked or source is corrupted: (1) Boot Safe Mode and run SFC again (Method 3)—Safe Mode prevents background processes from locking files SFC needs to replace, (2) Run DISM RestoreHealth (Method 1)—SFC pulls repair files from component store; if store is corrupted, SFC can't get clean files; DISM repairs store first, (3) Check SFC log to identify specific files—findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log > sfcdetails.txt; look for "Cannot repair member file" entries and manually replace those files (Method 7), (4) Run offline SFC from installation USB (Method 4)—scans Windows while not loaded, ensuring no file locks, (5) Check disk for errors—chkdsk C: /f /r schedules scan on restart; bad sectors prevent file writes (Method 6). After trying these, run SFC again—should report "did not find any integrity violations" if successful.

Q: What's the difference between DISM and SFC? Which should I run first?

A: DISM and SFC serve different repair functions in hierarchy: DISM (Deployment Image Servicing and Management) repairs Windows image and component store (C:\Windows\WinSxS)—the repository of all Windows files from which repairs pull clean copies; if component store corrupted, all downstream repairs fail. SFC (System File Checker) scans actual in-use system files and replaces corrupted ones with clean copies FROM component store. Think of component store as warehouse, SFC as delivery truck—if warehouse damaged, truck has no good products to deliver. Correct order: Always run DISM before SFC. Command sequence: (1) DISM /Online /Cleanup-Image /RestoreHealth (repairs store, 10-30 min), (2) sfc /scannow (repairs system files using fixed store, 20-60 min). If DISM fails with 0x800f081f, run DISM with installation media source (Method 2). Running SFC without DISM is like trying to fix house foundation with rotten lumber—repairs fail because source material is bad.

Q: How do I know if DISM or SFC actually fixed anything? The messages are confusing.

A: Interpreting repair tool results: DISM messages: (1) "The operation completed successfully" = component store repaired or was already healthy, (2) "The restore operation completed successfully" = corruption found and fixed, (3) "Error: 0x800f081f" = cannot find source files online; use Method 2 with installation media. SFC messages: (1) "Windows Resource Protection did not find any integrity violations" = no corruption found (good), (2) "Windows Resource Protection found corrupt files and successfully repaired them" = corruption fixed (check CBS.log for details), (3) "Windows Resource Protection found corrupt files but was unable to fix some of them" = partial fix only; files remain corrupted (continue troubleshooting), (4) "Windows Resource Protection could not perform requested operation" = scan failed to run (service or permission issue). To see exactly what was repaired: Check detailed logs: (1) DISM log: C:\Windows\Logs\DISM\dism.log, (2) SFC log: extract with findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log > sfcdetails.txt. Look for timestamps during your scan and "Successfully repaired" or "Cannot repair" entries.

Q: I've tried everything—DISM, SFC in Safe Mode, offline scan—but errors persist. What's my last option before reinstalling Windows?

A: If all standard repairs fail, escalate to these final methods: (1) In-place upgrade (repair install)—download Windows ISO matching your version, run setup.exe from within Windows, choose "Keep personal files and apps"; this reinstalls Windows completely while preserving data, effectively replacing all system files (1-2 hours, most effective non-destructive option), (2) System Restore to earlier point—if corruption started recently, restore to before problem began: search "Create restore point" → System Protection → System Restore; only works if restore points exist, (3) Reset PC with Keep Files—Settings → System → Recovery → Reset this PC → Keep my files; reinstalls Windows, removes apps but keeps personal files (less thorough than in-place upgrade but faster), (4) Manually replace corrupted files identified in SFC log—extract files from install.wim on installation media using DISM or 7-Zip, take ownership of corrupted files, replace manually (Method 7—tedious but works for small number of files), (5) Clean Windows installation—backup data, boot from USB, delete all partitions, fresh install; 100% effective but most time-consuming. In-place upgrade is recommended last resort—gives you fresh Windows without losing data/apps.