SFC /SCANNOW Command - System File Checker

How to Repair Windows 7 System Files with System File Checker​

   Information

The sfc /scannow command (System File Checker) scans the integrity of all protected Windows 7 system files and replaces incorrect corrupted, changed/modified, or damaged versions with the correct versions if possible.

   Tip

If you get the Windows Resource Protection Could Not Start the Repair Service error when trying to run SFC, then make sure that the Windows Modules Installer service is enabled, click on Start, and set to Manual.

Services - Start or Disable

OR

Copy and paste the command below in the elevated command prompt, and press Enter. After the Windows Modules Installer service has started, try running the SFC command again

net start trustedinstaller

   Note

The KB3022345, KB3035583, and KB3068708 updates will cause SFC to give you a false mismatch message in SFC for files related to these updates.

You can safely ignore these results in your SFC details since it will not affect SFC from being able to repair other system files.

   Warning

Be aware that if you have modified your system files as in theming explorer/system files, running sfc /scannow will revert the system files such as explorer.exe back to it's default state. Make the appropriate backups of your system files that you have modified for theming if you wish to save them before running sfc /scannow.

:note: For the updated Windows 10 tutorial, please see - SFC Command - Run in Windows 10 - Windows 10 Tutorials

CONTENTS:

• Option One: To Run the SFC /SCANNOW Command at Boot
• Option Two: To Run the SFC /SCANNOW Command in Windows 7
• Option Three: How to See and Read Only the "SFC" Scan Results from the CBS.LOG

OPTION ONE

To Run the SFC /SCANNOW Command at Boot

1. For how, see METHOD TWO at this link: SFC /SCANNOW : Run in Command Prompt at Boot

   Note

Using OPTION TWO below is recommended if able.

If you would like to get help with your SFC issue, then be sure to upload and attach your sfcdetails.txt file from OPTION THREE below in your post.

OPTION TWO

To Run the SFC /SCANNOW Command in Windows 7

1. Open an elevated command prompt or an elevated PowerShell, and do step 2 or 3 below for what type of scan you would like to run.


2. To Scan and Repair System Files
NOTE: Scans the integrity of all protected system files and repairs the system files if needed. Please see red WARNING box at the top of this tutorial.
A) In the elevated command prompt, type sfc /scannow, press Enter, and go to step 4 below. (see screenshot below)
NOTE: This may take a little bit to finish.


3. To Only Verify if the System Files are Corrupted
NOTE: Scans and only verifies the integrity of all proteced system files only. This command will not change your system files as in the red WARNING box at the top of this tutorial.
A) In the elevated command prompt, type sfc /verifyonly, press Enter, and go to step 4 below.
4. When the scan is complete, hopefully you will see all is ok like the screenshot below.

   Note

• If SFC could not fix something, then run the command again to see if it may be able to the next time. Sometimes it may take running the sfc /scannow command 3 or more times to completely fix everything that it's able to.
• If not, then download and run the 32-bit (x86) or 64-bit (x64) System Update Readiness Tool for your same installed 32-bit or 64-bit Windows 7, restart the PC afterwards, and try the sfc /scannow command again.
• If still not, then try using OPTION ONE above to run the sfc /scannow command at boot.
• If still not, then you can attempt to run a System Restore using a restore point dated before the bad file occured to fix it. You may need to repeat doing a System Restore until you find a older restore point that may work.
• If still not, then you can use the steps in the TIP box in the OPTION THREE section below to manually replace the files that SFC could not fix if there are not to many fix.
• If there are to many files to manually fix, or you prefer not to use OPTION THREE below, then you could do a repair install without losing anything.

If you would like to get help with your SFC issue, then be sure to upload and attach your sfcdetails.txt file from OPTION THREE below in your post.

5. When done, close the elevated command prompt.

OPTION THREE

How to See and Read Only the "SFC" Scan Results from the CBS.LOG

   Note

When SFC runs, it logs it's actions into the C:\Windows\Logs\CBS\CBS.log. The steps in this option will show you how to see only the specific SFC entries with the [SR] tags in this CBS.log. This can be helpful to show you what files SFC could not fix automatically if you wanted to try and manually replace them.

1. Open an "elevated command prompt" (right click -> Run as administrator).

2. In the elevated command prompt, copy and paste the command below, and press Enter. (See screenshot below)
NOTE: This will place a sfcdetails.txt file on your desktop with only the SFC scan result details from the CBS.LOG in it.

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

3. Close the elevated command prompt.

4. Open the sfcdetails.txt file on your desktop to see the SFC scan details in the CBS.LOG.

5. You can safely delete the sfcdetails.txt file afterwards if you like.

   Tip

If you need to replace a corrupted system file that SFC cannot fix, then this will show you how to by extracting a new copy directly from your Windows 7 installation DVD.

Extract Files from Windows 7 Installation DVD

That's it,
Shawn

Related Tutorials

---

• How to Run the System File Checker in a Command Prompt at Boot
• How to Do a System Restore in Windows 7
• How to Do a Repair Install to Fix Windows 7
• How to Run Disk Check in Windows 7
• How to See Windows 7 Reliability and Problem History with Reliability Monitor
• How to Extract Files from the Windows 7 Installation DVD
• How to Troubleshoot a Problem by Performing a Clean Startup in Windows 7 or Vista

 

[lehnerus2000]

Preferred Option

I'm going to recommend a clean reinstall (as my preferred option).
He has a lot of random stuff on his laptop.
I'd be surprised if he still uses all of it (he tends to install programs and then only use them once or twice).

It doesn't take that long to reinstall Windows and programs (and he has an SSD).
He just started 2 months Long Service Leave (that should be ample time).

If he doesn't want to do that, then I'll follow the "view the CBS log and replace the corrupt files" option.

 

[Brink]

Agreed. Clean installs always (well usually) give good results.

 

[Wexprestart]

Can somebody please help me. I tried sfc/SCANNOW and a massage saying 'you have to be an administrator running a console session in order to use the sfc utility'. I hve only one user account in this laptop and it is an administrator account. Please help me with this problem

 

[Golden]

Hi,

You need to do this:

http://www.sevenforums.com/tutorials/783-elevated-command-prompt.html

1. Click Start

2. In the search box, type cmd
3. In the list that appears, right-click on cmd.exe and choose Run as administrator
4. In the command window that opens, type sfc /scannow and hit enter.

Regards,
Golden

 

[djbillyd]

sfc/scannow

Brink, when I first posted on this thread, it was because ny "Windows Explorer" was running too slow to be bearable. I assumed that through all of the comments and tests and scans, that I would be working OK. Well, PHOOEY to that! Is there anything we may have missed trying to find a solution to this problem? It stopped for a long time, but started again last night. This is the system that I do EVERYTHING on, so you can imagine how frustrating it is to have the primary system tool screw up like that.

Any new suggestions as to why Explorer even does that?

 

[Brink]

Hello Billy,

Sorry to hear that it's acting up on you again.

You might see if doing a system restore using a restore point dated before this started again may be able to undo what caused it and fix it.

 

[djbillyd]

sfc/scannow

Yeah, I did a "Startup Repair", which said it couldn't fix the problem, and sent a report, and it has worked since. I don't know what this is...:shock:

 

[Brink]

Glad to hear it has worked since.

 

[catch22]

Quick question about SFC.. How do I read the logs?
is a

  0000032f [SR] Beginning Verify and Repair transaction
 Repair results created:

an indication that something has been fixed or is that general output? after that snippet, there was some "move file" commands taking place..

 

[Brink]

Hello catch22,

If you like, use OPTION THREE to create a sfcdetails.txt file, and upload it. I'll be happy to take a look at it, and post with some explanations to help read it.

 

[catch22]

well, I just ran it again, it said Windows Resource Protection didn't find any integrity violations. Is it still plausible to run it to detect errors?

 

[Brink]

That message means that it didn't find anything wrong with your system files.

 

[notis]

...Hello friends....
...Can someone help me to understand..., when I "run" sfc /scannow, in cbs.log, I found "thousand" of:
-Move File: Source = [....] "\SystemRoot\WinSxS\Temp\PendingRenames\...........cdf-ms", Destination = ......-
..what it means (about..), after the procedure (scannow), everything will be o.k.? is it a critical problem?
....Thanks for informations ..(if any or not..)

 

[Brink]

Hello Notis,

Please go ahead and post back with your uploaded sfcdetails.txt file from OPTION THREE, and we'll take a look at them to see what all it did.

 

[notis]

Hello Brink and thank you..
I didn't want to "bother" you, for a deep analyse...because soon (hoping..), I'll clean install...
But, very often (maybe always!) I see in cbs.log this "event" of -Move file....Destination...
...and I wanted to learn "at least"..what is about...Also I am sure other people have the same question...
...So I post the cbs.log where I see this procedure...and I attach also the sfcdetail.txt you asked, where..(surprise!)
...is just ONE!..only repair....I'm very interested to get any information...about..
Thanks again...

View attachment 258089 View attachment sfcdetails.txt

 

[Brink]

notis,

The SFC log shows that it found the file below corrupted. It was able to repair it, so you're all good.
C:\Windows\System32\lpremove.exe
That file is for MUI Language pack cleanup.

 

[notis]

Thank you Brink.
....thanks for your patience too...

 

[Brink]

You're most welcome notis.

 

[Juxxize]

2. In the elevated command prompt, copy and paste the command below, and press Enter. (See screenshot below)
NOTE: This will place a sfcdetails.txt file on your desktop with only the SFC scan result details from the CBS.LOG in it.

when I opened the file sfcdetails.txt in notepad it was empty, is that right?

 

[Brink]

Hello Julie,

Only if you didn't run SFC first.

Hope this helps for now,
Shawn