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

 

[Brink]

You're welcome.

Since it does run fine in Safe Mode, you might see if you may be able to use the tutorial below to troubleshoot and hopefully find the culprit.

http://www.sevenforums.com/tutorial...ation-conflicts-performing-clean-startup.html

 

[zyphodb]

Thanks I'll try that, as far as system restore goes, I can't get it to show me any earlier restore points before yesterday when I d/l ed the update that caused the problem & that one doesn't seem to work, v.fustrating especially on a less than 6 month old PC

 

[zyphodb]

Thank you very much that seems to have worked, I'm shocked by the result though, seems like the problem app was avast free edition, which iv'e used for years with no problem on several PC's
Am now installing AVG which I haven't used for many years, hopefuly this will solve it...

 

[zyphodb]

great, problem solved, still can't quite beleive that avast's latest update totally screwed my OS but you live & learn, again many thanks Brink

 

[Brink]

You're most welcome Zyphodb. Yeah, sometimes there are bugs even in the most reliable programs.

 

[djbillyd]

Are your games folders in the program files on your C: drive? If, in safe mode, you can open the program files folder and see if the setup files are in the folder too. If they are, when you do the clean install you will still have a "Windows.old" folder on the C: drive, and the program files folder will be in there (Windows.old) too. IF the setup files are there, just reinstall the games. Otherwise, you will need to network that computer, somehow, and migrate the game files to it, for storage.

If none of this works for you, the Brink, I'm sure, will guide you where you need to go.

BTW, the games might be the cause of your troubles. Did you do the "uncheck drill" when you were installing them?

 

[djbillyd]

My bad! I didn't see the resolution in my email. But I told you, Brink is the man!!!

 

[zyphodb]

All working fine now thanks BTW what is the 'uncheck drill'?

 

[zyphodb]

Oh sry u mean the msconfig/services thing? no but I'll know for the future, sry just got up, a bit dense...

 

[djbillyd]

Nah, I meant the adware check boxes in the install process. Some programs have an "offer" on several of the dialogue pages in the process. If you just click "Next" without reading them, you'll have crap for days on your system. I'm sure you've seen them. They'll already have a check mark in them, so I call it the "uncheck drill"!

 

[mag3]

I've run SFC a couple of times. It seems my files are all in tact. But I'm curious as to know just how it detects an inconsistency in a given module. To what does it compare the given file? Or is it some kind of CRC or hash check or something? I ask because it never asks me to load the original install media (which wouldn't help anyway if I've done system updates or service packs). Biggest worry is that a rootkit can be developed to circumvent it. I've had my battles with rootkits. :mad2:

Thanks.

 

[zyphodb]

Ah right yes Iv'e done that, I learnt that a long time ago, Of course I might miss the odd one if I'm drunk etc. when I install em lol

 

[djbillyd]

Mag, I wondered that too, but didn't quite know how to ask that "intelligent" question.

 

[metalcut]

I dont know if this is the right place for this but I am having a freaking terrible time trying to fix these .net problems with my computer. This is the result of my sfc /scannow log and I can't fix these issues at all:

[l:22{11}]"dot3api.dll" of Microsoft-Windows-Dot3svc, Version = 6.1.7601.17514, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
2013-10-14 20:19:57, Info                  CSI    00000092 [SR] Cannot repair member file [l:22{11}]"dot3api.dll" of Microsoft-Windows-Dot3svc, Version = 6.1.7601.17514, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
2013-10-14 20:19:57, Info                  CSI    00000093 [SR] This component was referenced by [l:202{101}]"Microsoft-Windows-Foundation-Package~31bf3856ad364e35~amd64~~6.1.7601.17514.WindowsFoundationDelivery"
2013-10-14 20:19:57, Info                  CSI    00000096 [SR] Could not reproject corrupted file [ml:520{260},l:46{23}]"\??\C:\Windows\System32"\[l:22{11}]"dot3api.dll"; source file in store is also corrupted


2013-10-14 20:26:50, Info                  CSI    000001b2 [SR] Beginning Verify and Repair transaction
2013-10-14 20:26:53, Info                  CSI    000001b4 [SR] Cannot repair member file [l:24{12}]"mscorjit.dll" of NetFx-MSCORJIT_DLL, Version = 6.1.7601.17966, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope neutral, PublicKeyToken = {l:8 b:b03f5f7f11d50a3a}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
2013-10-14 20:26:57, Info                  CSI    000001b6 [SR] Cannot repair member file [l:24{12}]"mscorjit.dll" of NetFx-MSCORJIT_DLL, Version = 6.1.7601.17966, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope neutral, PublicKeyToken = {l:8 b:b03f5f7f11d50a3a}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
2013-10-14 20:26:57, Info                  CSI    000001b7 [SR] This component was referenced by [l:156{78}]"Package_1_for_KB2742599~31bf3856ad364e35~amd64~~6.1.1.0.2742599-20_neutral_GDR"
2013-10-14 20:26:57, Info                  CSI    000001ba [SR] Could not reproject corrupted file [ml:520{260},l:102{51}]"\??\C:\Windows\Microsoft.NET\Framework64\v2.0.50727"\[l:24{12}]"mscorjit.dll"; source file in store is also corrupted

any help for this?

 

[Brink]

Hello Metalcut, and welcome to Seven Forums.

See if doing what's listed in the blue Note box under step 4 in OPTION TWO may help.

 

[metalcut]

Hello Metalcut, and welcome to Seven Forums.

See if doing what's listed in the blue Note box under step 4 in OPTION TWO may help.

Thanks for the welcome

I tried those steps. I had to download the iso image of windows 7 home premium from the linked site because its a refurbished dell that didn't come with a setup cd/dvd. The file mscorjit.dll is not a part of that iso file so I had to download that from a different site. I did replace the dot3api.dll with all of the take ownership commands and replaced it following the steps and it still didn't do anything. sfc /scannow STILL results in those 2 files being corrupt.
There are quite a few programs that use mscorjit.dll and right now I cant use any of them

 

[Brink]

Using the System Update Readiness Tool to repair the component store, then running SFC again afterwards didn't help?

If not, then you might consider a repair install to fix any remaining corrupted system files.

 

[metalcut]

I ran the readiness tool and it installed a hotfix. After I rebooted I did another sfc /scannow ( a couple more times actually) and the same files were still giving the same errors and the programs that need mscorjit.dll still will not run. I was really hoping to not have to repair/format win7 for 2 measly files.

What I really don't understand is I did a manual replacement of those 2 files (dot3api.dll and mscorjit.dll) and that still didn't work. why in the world would that fail?

 

[Brink]

Most likely their hashes don't match with a newer version from an update.

What issues are you having other than the corrupted files? If none, then I wouldn't worry about it. If only with .Net Framework, then you might see if reinstalling that version may help.

Download .NET for: Desktop, Server & Development | Microsoft .NET Framework

 

[metalcut]

The mscorjit.dll is the file that is killing me. I have a few programs that require that file and every time I try and start those programs I get the "cannot find mscorjit.dll" and the program closes with no other chance to open the program. I have uninstalled and reinstalled every version of .net I could find hoping it would fix.

edit: I have been running through Aaron Stebner's blog trying to find something that sticks.
Aaron Stebner's WebLog - Site Home - MSDN Blogs