SFC /SCANNOW Command - Run in Windows 8

How to Run "SFC /SCANNOW" Command at Boot or in Windows 8 and 8.1​

   Information

The SFC command scans the integrity of all protected system files and replaces incorrect versions with correct Microsoft versions.

This tutorial will show you how to run the sfc /scannow command at boot or in Windows 8 to attempt to repair corrupted or modified system files.

   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/tap on Start, and set to Manual.

Services - Start, Stop, and Disable in Windows 8

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

If SFC is unable to repair corrupted system files because the store (source) is corrupted, then you could run the Dism /Online /Cleanup-Image /RestoreHealth command to fix Windows component store corruption, then afterwards try running the SFC scan again.

   Warning

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.

CONTENTS:

• Option One: To Run SFC /SCANNOW Command at Boot
• Option Two: To Run SFC /SCANNOW Command in Windows 8
• Option Three: How to View Only the "SFC" Scan Results from the CBS.LOG

OPTION ONE

To Run SFC /SCANNOW Command at Boot

1. Open a command prompt at boot.

2. In the command prompt, type diskpart and press Enter, then type list volume and press Enter. (see screenshot below)



3. Make note of the drive letters for your boot drive (ex: 350MB "System Reserved" partition) and Windows 8 drive, then type Exit and press Enter. (see screenshot above)
NOTE: If you do not have a "System Reserved" partition, and are not multi-booting with another operating system, then the boot drive and Windows 8 drive may be the same drive letter.

4. In the command prompt, type the command below and press Enter. (see screenshot below)
NOTE: You will see a blinking cursor at the prompt until finished. This will take a while to finish running though.


sfc /scannow /offbootdir=C:\ /offwindir=D:\windows

   Note

You will need to substitute the drive letter of the partition/volume where your system boot files are stored in the offbootdir=C: part of the command above instead.[

You will need to substitute the drive letter of your Windows 8 partition/volume in the offwindir=D: part of the command above instead.

5. When the scan is complete, hopefully you will see an all is ok message like below.




6. Close the command prompt, and restart the computer to start Windows 8.

   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 times restarting the PC after each time to completely fix everything that it's able to.

If not, then run the Dism /Online /Cleanup-Image /RestoreHealth command to repair any component store corruption, restart the PC afterwards, and try the sfc /scannow command again.

If still not, then you could do a refresh of Windows 8, or run a System Restore using a restore point dated before the bad system file occured to fix it. You may need to repeat doing a System Restore until you find a older restore point that may work.

When running SFC offline (at boot), SFC logging in the CBS.log file is not supported to be able to create a sfcdetails.txt file in OPTION THREE below.

OPTION TWO

To Run SFC /SCANNOW Command in Windows 8

1. Open an elevated command prompt or elevated PowerShell.

2. In the elevated command prompt or PowerShell, type sfc /scannow and press Enter. (see screenshot below)
NOTE: This may take a while to finish running.



3. When the scan is complete, hopefully you will see an all is ok message like the bottom screenshot below.
NOTE: Luckily SFC was able to repair my corrupted system files automatically.

   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 times restarting the PC after each time to completely fix everything that it's able to.

If not, then run the Dism /Online /Cleanup-Image /RestoreHealth command to repair any component store corruption, 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 could do a refresh of Windows 8, or 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 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 THREE

How to View 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.

When running SFC offline (at boot) in OPTION ONE, SFC logging in the CBS.log file is not supported to be able to create a sfcdetails.txt file.

1. Open an elevated command prompt or elevated PowerShell.


2. In the elevated command prompt or PowerShell, copy and paste the command below and press Enter.
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. When finished, 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:

If you have to many files that are corrupted, then run the Dism /Online /Cleanup-Image /RestoreHealth command to repair any component store corruption, restart the PC afterwards, and try the sfc /scannow command again.

If you only have a few, then you could manually extract a new copy directly from your Windows 8 installation DVD or USB thumb drive, or ISO file if in a virtual machine.

Extract Files from Windows 7 Installation DVD

That's it,
Shawn

Related Tutorials

---

• How to Refresh Windows 8 and 8.1
• How to Reset Windows 8 and 8.1
• How to Use DISM to Fix Component Store Corruption in Windows 8 and Windows Server 2012

 

[JaidynM]

Another great tutorial, Shawn.

 

[Brink]

Thank you Jaidyn.

 

[Mike Lonewolf]

Thanks Shawn! I saved these tutorials for use in the future, really nice job.

 

[CB]

Thanks Shawn! I saved these tutorials for use in the future, really nice job.

Me too. Thanks Shawn.

 

[Brink]

You're most welcome Mike and Kevin. Thank you.

 

[sunyeon]

great tutorials ^^ but, like my case i already do sfc scan
and then can open the "PC Settings" but when i want to browse a picture
to change user picture it won't pop-up anything. can you help me ?

 

[Brink]

Hello Sunueon, and welcome to Eight Forums.

That needs to be asked in a new thread instead since that isssue is not related to this tutorial.

 

[spddemun]

I'm running this now, [DEL]dumb question--how will I know all is well when it's finished? Will it state errors?[/DEL]

Never mind, I see the example in the tutorial.

[DEL]If so, I run again, correct?[/DEL]

If there are errors it cannot fix, it will say such and ask me to run again?

 

[Brink]

Hello spddemun,

SFC will only be able to attempt to fix system files. Anything that it repairs or cannot fix will be included in the sfcdetails.txt file that you can create in OPTION THREE. Sometimes it may take running SFC a few times or at boot to fix some files in use though.

 

[spddemun]

OK, thanks. Just completed and my log shows it Repaired 0 Components.

I used the Exec. Cmd. Prompt, so I should try from Boot now, or repeat the option I just used.

I did a [DEL]Reset [/DEL] Refresh few days earlier and it only fixed 1 item (still left with 2 unfixed).

 

[Brink]

What is showing that cannot be repaired?

Please upload your sfcdetails.txt file if you like, and I'll be happy to take a look at it to see if I may be able to help.

 

[spddemun]

I meant it is showing that NOTHING was fixed because it found zero errors.

At this point, I'm ready to start over--working on problem in this thread.

Since there are no errors (found), do you recommend I try again, or go for (another) Refresh?

 

[Brink]

Ah, ok. Well, it just shows that you don't have a problem with your system files.

Hopefully you'll get a solution for your issue in that thread soon.

 

[spddemun]

Thanks. Has me jumpy to not install on other machines until I get this resolved. Know this forum is the best, so hopeful!

 

[Narayan]

Very nice and Helpful Tutorial, Great work Shawn....

 

[Brink]

Thank you Narayan. I'm glad it could help.

 

[onedoggy]

Awesome tutorial. I do appreciate the time and expertise that went into producing it. I find the need for it disturbing! That means mine is not an isolated problem, that lots of us (hundreds, thousands, millions?) are sitting here with new PCs loaded with software that requires these tutorials to be written. And used. Long down-time, lots of my-time running hopeful fixes....I was there for windows 3.1 and have been here with all the successors but this time, I am done. The need for tutorials like this have finally converted a die-hard Windows woman into a Mac person. Windows 8 is the most non-functional garbage ever.

 

[Brink]

Hello Onedoggy,

This function in this tutorial is available to help users when their system files get corrupted for whatever reason. Usually by the user's own mistakes, or by some software installed by the user or OEM.

 

[HippsieGypsie]

Awesome tutorial. I do appreciate the time and expertise that went into producing it. I find the need for it disturbing! That means mine is not an isolated problem, that lots of us (hundreds, thousands, millions?) are sitting here with new PCs loaded with software that requires these tutorials to be written. And used. Long down-time, lots of my-time running hopeful fixes....I was there for windows 3.1 and have been here with all the successors but this time, I am done. The need for tutorials like this have finally converted a die-hard Windows woman into a Mac person. Windows 8 is the most non-functional garbage ever.

Welcome to Windows EightForums, onedoggy.

Sorry to hear you're having so many problems with your new machine, especially if after spending hard-earned money on it. Then there's the elimination of much exciting anticipation when things go south with it. I can relate to your frustration, for I bought this Acer tower (please see specs) with Windows Vista preloaded. Ugh! Not a good experience whatsoever! "How unstable of an OS this thing is and quite a resource hog", or so I thought at the time. It ran a little faster than my old Gateway with 98SE on it, but was far more unstable.

It got to be where I was fixing the blasted thing more than using it! I was very busy at the time professionally and didn't need the headaches.

Lol! Like you, I was finished with Windows forever!, but with me I started to look into Linux. Like I said, at the time I was very busy professionally trying to run a business with it, so setting up and learning a whole new system was questionable. Luckily 7 came along, which ran quite nice with very little problems.

While using 7 I found out that it really wasn't a Vista OS fault, although as an OS compared to others it was quite a resource hog. It was more that Acer OEM released and sold the machine with far too less RAM in it to run Vista efficiently. While using 7 I upgraded the RAM in it to maximum 2GB, which probably Vista would've ran fine with. It made a big difference with 7 also.

Then with upgrading with fresh install to 7 I didn't carry along the Acer OEM crapware. More resources saved, although I had to contend with the OEM recovery partition which just sat there unused. Lol + 1/2 again! If you stick around you'll learn that I'm not the savviest of users. I botched up trying to remove that partition unsuccessfully only to be left missing about 120GBs of my hard drive and not being able to see the partition. Luckily I didn't destroy the HD! Thanks to this forum I found a nice little free utility lately that's able to see the partition. I will post on another thread to get help with fixing that problem.

Anyhoo, no OS nor machine is perfect coming out of the box, but I dare say it's rather from other sources, not the OS itself. Admittedly MS made some blunders with 8 rushing it out the door so far as design features, but I think most find that it is a rather stable OS.

This article covers most of the problems: www.eightforums.com/showthread.php?t=32157

I don't know what you bought, but OEM "brain-burn crapware" maybe another problem that you are having, although I realize that some of it is quite useful. Some of it goofs up machines. Sometimes we install programs that may not be compatible or install programs in the wrong way. I feel many here will attest to that.

We will be more than glad to help you with your problems, if that's what you decide to do. If so, please fill out your system specs so to help us help you better.

My apology if you feel this was long-winded > I'm sure all know I can be! Good luck to you and again welcome.