Overview of SFC scannow
SFC (short for system file checker) is a Microsoft Windows tool, which is located in
C:\Windows\System32 folder. It allows you to scan for or restore corrupted Windows
system files. In Windows Vista, Windows 7, Windows 10, system file checker is
integrated with Windows Resources Protection (WRP), which is used to protects
registry keys and folders together with critical system files.
The Windows Modules Installer service (TrustedInstaller.exe) has full access to
Windows Resource Protection files and registry keys, which allows you to modify
WRP-protected resources. It needs to be running when you restore missing or
corrupted WRP resources. And Administrators no longer have full rights to system
files.
How to run system file checker in Windows 7/8/10?
Step 1. Type cmd in the search box,
select it from the start menu list and run as administrator.
Step 2. Type sfc /scannow in the command prompt and
hit Enter.
Step 3. The process will take some time. You just need to wait and
exit this window.

NOTE: If there is no problem or your problems cannot be fixed, you will receive some
message in the command prompt window
That means that you do not need to do anything. Your computer does not have any
missing or corrupted system files.
- Windows Resource Protection found corrupted files and successfully
repaired them. Details are included in ...
That means your problem is fixed by sfc.exe command. And you do not need to do
anything.
That means that a problem occurs during running the scan and offline scan
command.
That means sfc / scannow cannot fix the corrupted files its find and you need to
do something.
In addition, you still can receive other messages, such as Windows Resource
Protection could not start the repair service, there is a system repair pending
which requires reboot to complete, you must be an administrator running a console
session in order to use the SFC utility, etc.
How to fix SFC scannow not working accordingly in Windows 7/8/10?
As mentioned above, you will receive different message according to your situation.
In the following, I will show you how to fix SFC scannow does not work accordingly.
See below and find the way that works for you.
Windows Resource Protection could not start the repair service
If you receive this error message, it means the Windows Modules Installer service
(TrustedInstaller.exe) is disabled. You need to enable it manually.
Here are two ways in the following. You can select the way you are familiar with.
Fix SFC scannow not running via Servcies
Step 1. Press Win + R to summon theRun window, type servces.msc and hitOK.
Step 2. Find Windows Modules Installer and
double-click it.

Step 3. Set Startup type as Manual and
then hit Apply and OK.

Fix SFC scannow not responding using CMD
Step 1. Type cmd in the search box
and run as administrator. Type usernameand password if prompted.
Step 2. Type the following commands and hitEnter after each one.

Step 3. Try SFC scannow commands again.
Windows Resource Protection could not perform the requested operation
Run chkdsk command
Step 1. Open cmd and run as administrator. Type username and
password if it prompts.
Step 2. Type chkdsk C: /r in the command
prompt window and hit Enter. Type Y and
hit Enter if it tells you that this volume is in use.

Step 3. Restart your computer and it will start to find and fix the
problem. After that, you can run SFC again.
Run SFC scannow command in safe mode
Step 1. Start your computer in safe mode. In Windows 7, you can
Start your computer, and press the F8 key repeatedly
before showing the Windows logo and then select Safe Mode under
the Advanced Boot Options. In Windows 10, you can click Restartwhile press and hold Shift key.
Step 2. Open cmd and run as administrator.
Step 3. Ensure the PendingDeletes and PendingRenames folder
on your system.
Step 4.Type sfc / scannow in the command prompt
window and hit Enter.
Change the security description
Sometimes, you will receive this error because this command cannot access WinSxS
folder. And then you need to change the security description of this folder
manually.
Step 1. Open cmd and run as administrator. Type username and
password if prompted.
Step 2. Type ICACLS C:\\Windows\\winsxsand hit Enter.

Step 3. Reboot your computer.
Windows Resource Protection found corrupt files but was unable to fix some of
them
Ifyou receive this message and SFCscannow does not fix problem, you can try to use
DISM command to restore health.
Step 1. Open cmd and run as administrator. Type username and
password if prompted.
Step 2. Type Dism /Online /Cleanup-Image /RestoreHealth in
the pop-up window and press Enter.

SFC scannow not working system repair pending
You may also receive message: there is a system repair pending which requires reboot
to complete. To fix it, you can try DISM RestoreHealth as mentioned above. If it
does not work and you receive DISM doesn’t support servicing Windows PE with /Online
option, you can try the following.
Run another DISM command
Step 1. Open cmd at boot.
Step 2. Type the following command and hit Enter.
dism.exe /image:c:\ /cleanup-image /revertpendingactions

Delete registry key for pending system repair
Step 1. Type regedit and select it from the
start menu.
Step 2. In the registry editor, navigate to the following key.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RebootPending
Step 3. Right-click RebootPending key and selectDelete in the context menu.
Step 4. Exit this window and try SFC again.
Tested way to fix SFC scannow not working in Windows 7/8/10
System file checker is mainly used to restore missing or corrupted system files. If
SFC scannow will not work in Windows 7/8/10, you can try free partition manager AOMEI Partition
Assistant. It allows you to find and repair missing or corrupted system files.
In addition, you can use it to do more thing, such as resize partition, move
partition, fix extend
volume is disabled, add unallocated space to d drive, etc.
AOMEI Partition Assistant can satisfy the basic needs of the majority of users. But
if you want more advanced features or fix problems the standard edition cannot, you
can upgrade to AOMEI Partition Assistant
Professional.
How to fix SFC scannow not repairing?
Step 1. Download AOMEI
Partition Assistant and open it.
Step 2. Right-click the partition you want to check, select Advanced andCheck Partition option.

Step 3. Tick one of the check options and
click OK and it will start the progress.

Step 4. It will run the progress immediately, wait a minute and
click OK when the progress reaches 100%.

The way forward
System file checker is a very useful tool in Microsoft Windows, but somestime you may
find SFC scannow not working. In general, you will receive the corresponding message
that gives you a clue to find the solution, such as, Windows Resource Protection
could not perform the requested operation, Windows Resource Protection found
corrupted files but was unable to fix some of them,Windows Resource Protection could
not start the repair service, etc.
According to your own situation, follow the above way and fix SFC scannow not working
Windows Resource Protection. If you cannot fix it, you still can try free AOMEI
Partition Assistant to check partition and fix the missing or corrupted system
files. This tool is very easy to use, even for a beginner.