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What Is the System File Checker, and How Do I Run It?

In order to prevent malware from replacing critical system components with compromised copies, Windows works very hard to maintain the integrity of the system files on your machine. If you try to replace one of the “protected” files, you may get a message that the operating system has put the old approved version back. That’s “Windows File Protection”, now called “Windows Resource Protection”.

Unfortunately, there are occasional ways around system file protection. Sometimes it’s as simple as a hard disk error causing a system file to be damaged and become corrupt.

As a result, automated checking is nice, but sometimes you need to take matters into your own hands.

Enter the SFC, the System File Checker.

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System file protection

The basic premise behind system file protection is that Windows keeps additional information about all the files that are part of Windows. That additional information could be (but certainly isn’t limited to) the date/time stamp of the file, its size, and its cryptographic hash. When files are “officially” replaced (or updated by Windows Update), this database of information is also updated to reflect the new official files.

Every so often, Windows checks all those files to make sure they still match. That means that the time stamp, size, and hash value match what is expected. If they don’t … well, then something is wrong, and Windows will likely report the error.

Unfortunately, “wrong” can be the result of many different things:

  • Malware. Malware was one of the reasons system file protection was implemented in the first place. Malicious software would inject itself into the system by modifying Window’s own files. System file protection detects when this happens.
  • Set-up programs often replace system components with their own, sometimes breaking things. System file protection notices when this happens.
  • Random other failures.

So, what happens when a problem is found?

Repairing altered files

If you’ve ever searched for a system file on Windows, it’s not uncommon to find several copies:

  • The original file, used by Windows.
  • Previous versions of the file saved by Windows Update, so you can uninstall specific updates if needed.
  • Cached copies of the file, kept as a performance enhancement that loads the file more quickly when needed.
  • Back-up copies of the file.

It’s that last one that would be used to restore the file to its original state should something happen.


In addition, many systems now include a copy of Windows on a restore or recovery partition, which can also be used as a source for retrieving original copies of files that need to be restored.

When all else fails, the original Windows installation media might be used, if you have it.

In all cases, the repair process also checks that the copy it’s restoring is correct. If it fails to have the expected information, it will be skipped. Because many of those sources are on your hard disk, malware authors attempt to replace or damage them all to prevent the repair process from working.

SFC – the System File Checker

SFC is nothing more than a command-line tool that checks that all of the files covered by Windows system file protection are as they should be, and to try to repair those that are not. It’s a good utility to run when you suspect system files have been somehow corrupted, or even if you just think there’s “something wrong” with your system.

SFC requires administrative privileges. Right click on the start button, and click on Command Prompt (Admin).

Command Prompt (Admin)

(In earlier versions of Windows, locate the Command Prompt menu item in StartAll Programs, Accessories; then right-click Command Prompt and click Run as administrator.)

After confirming any UAC prompts, type “sfc /scannow” in the Command Prompt and press Enter.

SFC /scannow

This causes SFC to scan your system immediately. SFC can take several minutes to run. If you have installation media, such as a DVD, you might have it available, just in case SFC wants to replace a damaged file.

While it’s not documented anywhere, I’d reboot your machine if SFC replaces any system files. Why? I just like to be sure that the file replacement actually takes effect.

Microsoft has more detailed SFC documentation, including more options to check at boot time, control the size of the system file protection cache, and so on. There is also Windows Resource Protection documentation, which covers the mechanism Windows uses to keep your system files (and a few other things) safe automatically.

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155 comments on “What Is the System File Checker, and How Do I Run It?”

  1. Great resource Ed, thank you. In fact it might well solve a problem I experienced over the weekend :-). (FYI – I changed the link to go through my redirector.)

  2. I have a simple problem – I type Sfc.exe in the run box and it “pops up” for a split second – then disappears!! Have tried many times. I am not a computer expert – so I’m not exactly sure EXACTLY what to type at the command prompt (the 2nd route I’ve tried). Microsoft website isn’t much help.



  3. As the article you just commented on specifies:

    sfc /scannow

    should do the trick. If you’re having trouble, may be easier if you open a command prompt and do it in there, rather than the start-run box.

  4. When I type SFC /SCANNOW or SFC /SCANONCE, it shows me the following messages
    C:>sfc /scanonce
    Windows File Protection could not make the requested change.

    The specific error code is 0x000006ba [The RPC server is unavailable.

    THE INSTRUCTION AT “0x7c9105f8” referenced memory at “0x01b60010”. THE MEMORY COULD NOT BE “READ”.

  6. 1st – great site
    2nd – I’m having trouble with this. I’m missing note pad. so i followed your advice here. I read the article on what to do if don’t have a start up disk and then went about running the SFC. It found a problem and asked for the cd, it offerd the options to “Retry” “More Info” and “Cancel” I hit retry and it aked for the cd again( in a new box). I hit “Ok” and was hoping that it would ask for me to locate it, it didn’t how ever. My question is, did i do something wrong, or is they some other way to do this? Your help would be awsome if you have the time. I really miss my notepad. I’ve tried to include as much information as possible. And will provide more if asked. I’m not all that computer savy, so take it easy on me if this is a stupid question. 🙂
    Thank You in advance.

  7. I wanted to run SFC to check out a problem. Went to Run, typed in sfc/scannow and window box came back saying it cannot find sfc/scannow. Make sure I’ve typed correctly, etc. what has happened to that file? I recently installed, then uninstalled SP2, because I had all kinds of problems. Would that have anything to do with it?

  8. Leah: That second request for the CD should have included a BROWSE button that you should be able to use to locate the files requested.

  9. Thanks for you comment. I tryed again. Hoping that maybe I just missed it. I still didn’t see if, so i decide to take screen caps to see if I was being a ditz or if my program isn’t working right.
    Here is the url for the image of the frist box:
    and this is the second box:

    is this what i should be seeing?

    Again, I want to say thank you for being such a great guy about this.

  10. I’m not to sure where to ask you…but…My computer is having a major problem…it seems to me to be the power…when turned on under 115v only the fan runs and the computer won’t even turn on…and on the rare occasion it does it freezes after about 2 minutes….under 250v it will run but only for so long before it shuts off completely…I’ve restored my hard drive a number of times. Could it still be a virus…or something else?

  11. Are you sure your power supply can handle both voltages properly? At any rate, it does sound like a power supply problem, and I’d probably start by replacing that.

  12. Reboot. If it only boots into safe mode, there’s an error message somewhere along the way that tells you why. Correcting that error should resolve the issue.

  13. It probably tried to display an error message. Instead of using Start-Run, fire up a command prompt and enter the sfc command in it. That way if there’s an error message, you’ll see it and can correct whatever as needed.

  14. Heh … sorry.

    In most cases you’d click Start, All Programs, Accessories, and then Command Prompt.

    Or, click Start, Run and then type in “CMD” and hit OK.

  15. Hi Deborah.

    I’m not an expert on XP problems – just very familiar as I often push my PC’s to the limit.

    Anyway, I believe that you are not entering the full command line. If you just type SFC and then attempt to run it, nothing will happen as you haven’t stated any program options.

    What you need to do (in the above suggestion) is actually type the following in FULL in the run box, precisely as below…

    sfc /scannow

    …and then hit the OK button.

    Best regards,

  16. What does this SFC do if a file was updated through a security update, or a service patch? will this restore the older file ??

  17. gruebane: it should restore the updated software from an additional copy it installs on your hard drive when you installed the SP or patch.

  18. I have Outlook Express but I can’t send or receive any email. It always said the host POP3 couldnot be found. what is this and how can i corect it?

  19. Your POP3 server is part of the configuration for yoru email account. What server name to use should have been provided to you by your ISP.

  20. every time i try to log into my hotmail account I get the message “page can’t be displayed” or cannot find server. I need to check my email, it lets me put the email address in but it doesn’t load up the page. I need to get this resolved quickly as possible because I have important information I need to attend to. Thank you.

  21. dont know bout anyone else but i cannot even access my hotmail account, it just comes up with page cannot be displayed and i’ve heard about other ppl who have the same problem..anyone know wats goin on

  22. You need to run a command prompt (start, run and then type “cmd” and OK), and then run the sfc /scannow in the resulting command window.

  23. What is the System File Checker, and how do I run it?
    Well Leo explained very well. It is pretty simple and obvious to me.

    Here is another way to help you:
    Click the Start Icon / Run / Type:

  24. I ran SFC/scannow & expected a report when it was done – but none was produced. If a report was created, where should I look for it?

  25. What if the apps error does not cause a system crash, just a simple click ok,and it’s gone would you still run the SFC? IEXPLORE.EXE Application Error
    The instruction at “0x1001cbf1” referenced at “0x1001cbf1”. The memory could not be “read”. Click on ok to terminate the program. That’s the apps error i got twice in two days. what should I do about it. XP Home SP2 IE 6

  26. Yep, I found scannow kept stopping and asking for the cd but clicking ‘retry’ each time and the scan progressed. After many stops (maybe 10+ mins)the scanbar reached 100% and that was it…no ok message . Assume no problems found ?!

  27. Ok, i run sfc, but the Command Prompt window appears and immediately disappears… What now? Is there any tool in the web for checking the File System???

  28. Will this have affect to the Windows File System ONLY? I mean, will it maybe be important to reinstall some of my programs?

  29. Help, my Folder Options in the Tools menu of Windows Explorer has disappeared.

    I am using WinXP. This has occurred before and I got the remedy from Comp Active mag but I seem to have lost it.

    Can anyone please help me to restore this option. I remember it was quite simple really!!


  30. Hello,
    Thank you for all the advise you give it’s so helpful and welcomed. I tried to do ‘press Start, Run, and then type in SFC’, and I could see the black DOS box flicker on and then back off so fast it would make your head spin. I tried once more after 10 mins. and it was the same. Any suggestions please?

    Thank you,

  31. Leo,
    While your site was a help it didn’t fix my problem. Everything refers to the installation of Win Inst 3.1 but no one every mentioned going into Control Panel, Adm. Tools, Dbl Clicking Services, going down to Windows Installer, make sure it’s in manuel and then in the upper left corner of you screen click on Start. Now it works.

  32. When I try to run the System File Checker as outlined above, I get an error message stating that Windows cannot findSTC/scannow. What do I dO?

    • please follow the steps mentioned in the article ‘as verbatim’. you are running sfc from ‘run’ while the article clearly asks you to run it from the ‘command prompt’.

  33. For those who are having the “RPC server is unavailable” problem with sfc, the following registry edit / path variable fix may help. This is designed to fix the windows help and support center if this has stopped working, but in my case, also solved the sfc issue.

    > > At a command prompt, type SET
    > > If the value for WINDIR=%systemroot% (and if you have all the above
    > > mentioned problems, it WILL be 🙂 ) you need to apply the following
    > > fix:
    > >
    > > Run REGEDIT
    > >
    > > Go to HKEY_LOCAL_MACHINESystemCurrentControlSetControlSession
    > > Manager Environment
    > >
    > > in the right-hand pane, find the value WINDIR. You’ll notice it is of
    > > type REG_SZ. This is incorrect since it’s value (%systemroot%) needs to
    > > be expanded to what windows will eventually use (in my case,
    > > C:WINDOWS).
    > >
    > > What is happening is window is attempting to load the help and support
    > > module (and anything else that relies on the %windir% environment
    > > variable) by calling it %systemroot%pathtofilefile.dll instead of
    > > c:windowspathtofilefile.dll.
    > >
    > > DELETE the existing windir value.
    > > Make a new EXPANDABLE STRING VALUE, call it WINDIR and give it the
    > > %systemroot%
    > >
    > > This procedure basically recreates the WINDIR value as an expandable
    > > string.
    > >
    > > Reboot your system and watch your help and support center work for the
    > > first time in recent memory.

    As suggested in:

    Hope this helps

  34. I had the same problem, i.e., SFC not running as it should have. In XP SP2 (and all XP should have SP2) there is a repair and maintain instruction on Microsoft info pages. Look for it under Windows Repairs. Run it according to their instructions. You will need your Windows disc and patience. Run that, then cut and paste Leo’s coding for SFC in the Run box. Works like a charm.

  35. I get the message “missing dll” when starting up. I am going to try this to see if I can correct this problem. Also, today, I have had the BSOD (blue screen of death) twice. Am considering purchasing SpinRite. Hope I am computer savy enough to run it without making things worse. Thanks for your advice.

  36. Thanks for the tip w/ sfc. Another bit of info to add to this would be how to pull it up if the start bar is missing. I found by going into the command prompt and typing sfc/runnow i was able to scan withouth goingting through the ‘run’ option.

  37. I tried at least ten times to enter sfc/scannow & sfcscannow in the command line and it cannot be found. I guess that won’t work for me……What will???

    Hash: SHA1

    Make sure there’s a space between “sfc” and “/scannow”


    Version: GnuPG v1.4.7 (MingW32)


  39. I am having a problem with my check. First when i secdule a task(the one that requires you to restart your comp) it stops at 2 percent and never continues.) however, when i do the one that doesnt require you to do that its works perfectly fine. IT did mention something about Found folder. Any suggestions?

    Hash: SHA1

    Assuming you mean Chkdsk, not “check”, it sounds like a bad sector on the disk,
    offhand. I’d probably have you follow the recommendations in this article:
    (even though it’s about a slightly different scenario, these are the steps I’d
    have you do.)


    Version: GnuPG v1.4.7 (MingW32)


  41. I tried running the sfc and was unable to. This is the error message I have received when opeing OE. Nothing I do seems to fix this.

    This program has performed an illegal operation and will be shut down.
    MSIMN caused an invalid page fault in
    module SHLWAPI.DLL at 016f:70bd899f.
    EAX=00000006 CS=016f EIP=70bd899f EFLGS=00010206
    EBX=00000000 SS=0177 ESP=0056d04c EBP=0056d058
    ECX=0056ce44 DS=0177 ESI=00000000 FS=425f
    EDX=0056ce44 ES=0177 EDI=5ec041b8 GS=0000
    Bytes at CS:EIP:
    8a 03 84 c0 74 52 8a c8 f7 d1 f6 c1 80 0f 84 ea
    Stack dump:
    00000003 00000000 00000000 0056d1b8 5ec237b7 00000000 5ec041b8 00000006 00000016 00000000 00000000 0056d0b8 00000010 819b0228 00000024 bff7a3a0

    Hope you can help.


    Hash: SHA1

    SFC is still the answer. What does “unable to” mean?


    Version: GnuPG v1.4.7 (MingW32)


  43. As several others above, I ran SFC, confident that I would be able to point to the proper directory when asked to insert my Windows CD. I was not given this option — only ‘retry; more info and cancel’. When ‘cancel’ was selected, I was not given an option to browse for the correct directory’. I tried burning a CD populated with the I386 directory, but this didn’t work either! Any suggestions? Thanks, Marlene

  44. I keep getting the same error report ” IE has encountered an error and needs to close…”
    Then, my windows explorer is giving me a really hard time. It now does not work. So, I cannot access the ” My Computer ” Folder. What do i Do? does the SFC thig resolve these issues?

    Hash: SHA1

    I’d point you at this article:

    And sending error reports will not solve the problem



    Version: GnuPG v1.4.7 (MingW32)


  46. If you run the system file checker (sfc /scannow) and you get: “windows resource protection could not perform the requested
    operation” try this:

    -Reboot your PC, and after the BIOS screen keep pressing F8 to get to the advanced boot menu.

    -Choose Repair your computer

    -Login as Administrator or the equivalent

    -Open the command prompt, and type CHKDSK C: /F /R

    This will scan your hard drive for errors in the FAT (File Allocation Table). It will perform a physical scan of your hard drive and attempt to repair any errors it finds. The logic behind this step is that the SFC /SCANNOW won’t run properly b/c it cannot actually access the files on the hard drive.

  47. I tried to run SFC/scannow but was given an error in return saying Windows could not find…I have been trying to get my task bar/start menu and other options back up that disappeared after a disc scan…

    Hash: SHA1

    There should be a space between SFC and /scannow


    Version: GnuPG v1.4.7 (MingW32)


  49. Okay, I have been trying to use SFC for a while now, one time successfully. My question is : Can you run SFC without getting to the “Run” command? I have a problem with a PC not booting, giving me the “Missing NTLDR” error message and I want to use SFC to replace the missing NTLDR files and boot normally again. I notice that you can’t really run SFC from a command line prompt, or if you can, I am doing it wrong. Any help would be great, thanks…..Marty

    Hash: SHA1

    I’m not totally sure I understand your question, but:

    – you can run SFC /SCANNOW from the Start->Run menu item

    – you can run SFC /SCANNOW from within a command prompt

    You might try safemode, and you might try the recovery
    console as well, if things aren’t working for you.

    ALSO, I’m not 100% convinced that SFC will restore NTLDR. I
    could be wrong.


    Version: GnuPG v1.4.7 (MingW32)


  51. Hey leo I had to get rid of antivirus xp2008 and i dunno if i corrputed some things in the process
    Now add or remove programmes will not work:(
    Nothing happens at all when i click it
    I tried sfc but when i pressed enter it flashed up for a brief moment and then dissapeared
    Any help:s

  52. Leo,
    All of a sudden an XP PRO computer boots, but
    stops with the error message that the windowssystem32configsystem file is either missing or corrupted. The file exists and is about 5 meg, so it must be corrupted.
    I read your article about using sfc /scannow,
    however when I use the original OS CD to boot and get to a command prompt with the “r” recovery option, the sfc.exe is not an available file to run.
    Is it on the OS CD?
    If not then trying to fix a damaged system file
    that is keeping the OS from loading using the sfc
    command is useless. No START RUN available !!
    What am I missing? If it can’t be run from the Recovery Console, then you should tell your readers that for 95% of the time they can not fix a computer that is stuck because of a corrupted file.
    Greg Fiore

  53. Is there a potential problem when using SFC and you have updated your system with various service packs. It seems like some of those critical system files would have changed, and there you are putting in your ORIGINAL install disk with “old” system files on it.

  54. I just successfully ran System File Checker on my custom built PC using my Windows XP Home Edition master disk. Interestingly, the disk would not run in my CD drive, but ran perfectly in my combination Benq DVD writing drive. After the System File Checker ran, I saw no error messages. I have been trying to solve a problem, trying to determine why my front USB ports have stopped recognizing my Digital Concepts card reader/writer.

  55. I have my Windows XP Professional on a DVD. The SFC runs close to the end and then asks for Windows XP Professional CD2. I don’t have a second CD since it is on a DVD. I click Retry and it doesn’t accept the CD. How do I get around this?

  56. Hi Leo,
    I recently had a nasty Trojan called Prunnet.exe.
    I used various programs to attempt to remove it, which i think has been done successfully.
    Anyway, after running the anti-virus/anti-malware programs, I’ve been getting error messages, and once my computer shutdown because some vital system processes were not running.
    I think that the anti-virus programs may have deleted some system files, so i ran system file checker.
    After the scan, the scan completed (to my knowledge), but the small “windows file protection” window disappeared.
    Does this mean that all the system files are intact and undamaged?
    I anxiously await your reply.

    Unfortunately there’s no way to know. This article discusses: My anti-virus performed a virus removal but I still have a symptom, how do I get rid of it?

    – Leo
  57. …hey, mr. leo… i dunno if this is a virus or what, my laptop got an autorun thing… and i can’t delete it, i have an anti virus here but that autorun thing keeps invading my file, even my usb and cp were infected… what should i do>?

  58. I just found this site and so I’m new to finding information here. I was wondering if Mike Creel’s question posted on 1/28/08 has been answered and if so it would be great to read it. His question applies to me as well.

  59. Leo,
    I have only the original XP Pro CD.
    Usually this is useless because if I try & use it my system always says “the installed version is more recent”.
    So for just about EVERYBODY, who has the nearly 100 XP updates, including SP2 & 3, surely the advice you offer, to try & use the original CD is useless.
    This is the second comment on this topic which I hope you see fit to address.

  60. Leo, I installed IE 8 on my XP mach. Didn’t work. Removed it and IE 7 wouldn’t work. Removed it IE 6 worked. Reinstalled IE7 and all fixes & SP3. Works fine. Outlook Express now has a prob. Cannot open any links from outlook. Ran SFC /scannow. Ran to completion no problems. OE still not working for links. Any ideas?

  61. I am having problems controling iexplorer.exe How do i keep it from Crashing my computer. I’d like free safe download, I have Windows XP home Edition


  62. I have Windows XP. I do not have the file
    SFC/scannow. Please explain.

    There’s should be a space between SFC and /scannow

    – Leo

  63. I ran SFC /scannow. Window pops up saying – Please wait while Windows verifies that all files are intact and in their original version. When that got done, window went away. I didn’t see anything happen after that, so I tried running SFC ‘scannow again, and same window came on saying the same thing. What and how do you scan?

    You just did. If SFC finds no errors that’s how it behaves.


  64. Leo,
    when running SFC scannow, with the right XP SP3 CD in the CD-ROM drive, a window appears repeatly saying” Files that are required for windows to run properly must be copied tp the DLL Cache. Retry, More Information, Cancel”. Answering “Retry” makes drive light to twickle and the progress bar to go up a little until this window strikes again.
    “More Information” reports the following:”Possible reasons for this problem: 1.You may have inserted the wrong CD. (i.e., a different windows product CD than the version installed. 2. The CD-ROM drive in your system is nor functioning”.
    I confirmed that the CD is the right one and is updated to SP3 such as the version installed in the PC.
    After hundreds of retries the process ends up apparently well i.e. without further infornation. Can you realize what’s up?

  65. I have only the original XP Home ED. CD. It is useless to run “SFC /scannow” because if I try & use it my system always says I have the wrong CD inserted.

    So what is my option when I have upgraded to SP3, then installed multiple updates? I don’t want to run a repair install. I tried this once before with another problem. It installed original files which clashed with the Windows Updates. My OS was totally hosed.

    I want to obtain or reinstall the Search helper files which have suddenly gone missing. How do I get up to date ones ( or ones that are compatible with all the Win Updates?) using SFC?

  66. Hi Leo! I have had a problem with two computers in my home that I am sure is related to one of the sites I visit. As I only access approximately 10-15 total sites and am the only user, a virus seems the only possibility. 98% of the time, when I power up my monitor times out like it is recieving no video input. I have run “sfc /scannow”, but there have been no errors found. Since it has happened with both systems, I am sure I have a virus, but have no practical knowledge of what virus/virus(s) I may have, I have no idea how to proceed. Any suggestions?

  67. Ran SFC /scannow. Used original setup disk. Got a message that I needed setup disk 2. Hence this action did not solve my problem. I am going to the microsoft blog via an alternative browser. I remember seeing a wordperfect version of a fix to the problem.

  68. I have windows automatic updates and when my computer restarted after update for clock..I have no start button or taskbar and I ran sfc/scannow..I added explorer via task manager..nothing happened..I don’t have a windows cd because I have an hp that has system restore but now I can’t find it..please help..thx

  69. i just ran system file checker on a ubuntu/winxp system and upon reboot, am receiving error 17 from GRUB. i would never have run this utility if i had known it could interfere with my setup. you should have mentioned the possible danger to dual boot machines. do you have any advice on fixing this?

    Sorry, no. I think it’s highly unlikely that SFC did this. It just checks windows files and shouldn’t be poking around outside the Windows partition when it’s running.


  70. Hello Leo! Your newsletter is great! Now to the point. OS = Windows XP Home. I ran SFC /scannow and experienced the same as another poster – repeated msg asking for the CD. Took many retries. Window disappeared when bar reached the end. You state that is the way SFC act if it finds no errors.

    My system still does not work properly. Cannot access my Inbox email (can’t receive mail, but can send). Also, I cannot perform Restore actions. Msg keeps saying to pick a different date. This tells me that files are either corrupted or missing.

    Any ideas?


  71. to the one with the error 17 message in grub… Error 17 usually means that grub cannot find it’s menu.list file. Get a copy of the Ultimate Boot CD and it can restore grub automagically.

  72. I am using what I think is Windows 2009. I moved from Texas to Louisiana and suddenely my midi file folder in outlook express has disappeared. It contains midis that I have collected for years to send out with my emails. Can you tell me how to and/or where to find it along with instuctions.
    Thank you very much,

  73. Your Scannow fix worked great. The XP
    Oe8 would not get to the email, giving
    an “Oe has encountered problems, sorry”
    useless message. Tried Sys Restore to
    reboot but still not help. Tried the XP
    Add/Delete Components without success.
    The SFC did work. Thanks.

  74. For all of you who get errors from trying to run from the disk, it is because the Windows CD is not updated to the proper version. Most likely, it is SP1, and you need to have an SP2 CD(or SP3, etc.). Google “slipstream Windows CD” and you’ll probably find what you need. It tells you how to make your SP1 CD into a SP2.

  75. Hi Leo. I have real problem in that I lost Outlook Express when I inadvertently restored factory settings. Now, when I want to send pictures prompted by windows live, Outlook express box comes up, I enter the recipient’s address, press send, and then I get an error message .. lots of stuff followed by No, Server Error:998 Error Number Ox800CCC33. Can you advise please. Thanks

  76. I used the SFC /scannow and nothing happened, it didn’t even give any kind of error nor message. Does that mean there is nothing wrong with my files?

  77. Task bar and Start menu were not to be found in Win Vista. I am trying your method I did not get a error or Message if it has fixed the prob. I will reboot if it is required
    Thanks if it will work.

  78. I ran this in the cmd box.. it asks for my win sp svc pak 2 cd.. which i dont have, since my win xp has upgraded itself via internet. what can i do?

  79. I have Windows XP Service Pack 3. My Windows Update is not working. I have tried everything that Microsoft recommends but no luck. I ran SFC/scannow, and it said my files have to be copied to the DLL cache. I did not receive a Windows Installation CD with my computer, so I am stuck and have no idea what to do.

  80. when i typed sfc scannow,there is a message window cannot find problem is when windows page load it stop.sometimes it load normally,most of the time i go to safe mode,then shut down,then restart. it works. it is annoying.please help.

  81. I cannot open OE it says another version is running on the computer. It isnt so i am at a loss as to why this message appears. I have followed instructions on sfc/scannow -a window appears flashes then disappears. nothing happens. how can i get it to scan

  82. I run SFC fairly ofter, because I have plenty respect for it. It is one of the few tools to my knowledge which corrects errors in the operating system, which I seem to have too often.

    Is SFC supposed to run while one is in Safe Mode? If so, can you explain what issues may be keeping it from running in Safe Mode?

  83. hi, i can not open my internet explorer,what can i do?

    Depends entirely on what happens when you try and your OS version. Are you up to date? Scanned for malware with up to date scans? Not nearly enough info for me.


  84. I often run the SFC utility and I do have the OEM version of my O/S on CD ! I put the CD in my DVD/CD drive and tap the shift key to prevent the CD from auto run ,once the light stops flickering on the drive showing the system is trying to run the CD ,then I type SCF /scannow (note the space between the F & /) It takes about 20 miniutes to run and I have very high cvonfidence in this utility

  85. I have tried running SFC but it asked for CD & then said it couldn’t proceed as the operating system on the CD was older than the one on the computer. How can that be and what can I do about it please?

  86. How does the SFC handle an OS that has been service pack patched. Example: cd is XP sp0 and system is now on xp SP3?

    It typically refers to the original location of the service pack files, or it asks for that location if needed. There are also some scenarios were it doesn’t work.


  87. I was working on my computer one day, took a break and came back. My background was all that was on my desktop. I thought I could find the problem by using SFC but have never used it before. When I entered the command what I got was an instant entry of c:Documents and settingsadministrator> and a blinking cursor.
    What does this mean? I am assuming I have some registry error but how do I find out exactly what it is and how to correct it?

  88. I tried this to try to resolve a USB issue, but when it asks for a CD, there is no way to put in a system path. Therefore I can not continue as the CD that came with my Computer doesn’t work either.

  89. @Heidi
    This happens if you are running Windows 7. It’s the User Account Control protecting you computer against unauthorized access.

    To get around this click on the Start Button, select All Programs, scroll to the Accessories folder, then right click on Command Prompt and select Run as Administrator.

  90. I ran an sfc /scannow twice after copying i386 folder to my C: drive to check for errors, and both times it’s filled up my HD up to 2G worth of space. Is there a way to delete this built-up cache of files? Thanks, Leo!

  91. My videos downloaded from a hand held Flip/ Cisco camcorder got corrupted…I system restord to week ago+they play only if I open menu on the file+scroll to “Play on my Acerx193w”…double left click on file will default to first one played by double left click. Help?

  92. First off. BIG THANKS, LEO, for being retired and STILL giving back to others.

    Is it possible to set up Win7’s Task Scheduler to run SFC automatically?

    Oakland, CA

  93. Hello,
    Can SFC be used for repairing an “altered” appwiz.cpl in Windows Xp SP3?
    Altered means that i see all programs installed but i cannot change/uninstall the majority of them from within the appwiz.cpl.
    I can just see the entries the name but no possibility for change/uninstall.
    Thanks in advance.

    • I don’t understand the scenario you’re describing well enough to say yes or no, but I will say SFC shouldn’t hurt anything so why not give it a try. And of course, be backed up completely first (and always).

  94. I googled my problem, and your site come up. I get random windows message at no particular time it’s 2 windows once says copying, the other says to confirm file replacement, you can click yes, no, yes to all, or cancel. or x out. I’ve looked everywhere and cannot find this message, have no idea where or why i get it or what it means.

    I’m running windows xp.

    • That almost sounds like you are clicking on something and giving the computer a copy command. It might be accidental keystrokes you are doing. Sometimes mice are very sensitive, and trackpads on laptops can do various commands which catch you by surprise. So try to notice what you are doing with the windows pop up. Just a possibility.

  95. firstly thanks for being there Leo..many appreciate you and we in the Green Isle would call those who complain as above (some) begrudgers ….this what i got when i ran the check as advised by you
    “windows resource protection found corrupt files but was unable to fix some of them. details are included in the CBS.log windir\logs\CBS\CBS.log for example C:windows\logs\CBS\CBS.log. note that logging is currently not supported in offline servicing scenarios ”

    that was all it wrote …no solution offered thanx mr. gates.. am running 8.1 on a 2GIG MEMORY notebook only weeks old and is as slow as a tranqed tortoise lately.. i used up to date Superantispyware free and Loaris trojan remover latest version latest updates and Bitdefender antivirus plus 2015 up to date and full scan before the test and all clear



  96. I have Windows XP pro but when I tried to run the file checker it asked for my Windows CD but would not accept it, even though it had SP3 on it. After much trial and error here is what worked for me.

    Copy the I386 folder from the Windows CD onto C:\. Next click on the Start menu than Run. In the Run box type regedit. This opens the registry.

    Scroll down to a) hkey-local-machine b) Software c) Microsoft d) Windows e) Current Version f) Setup

    You will see two lines that need to be changed. They are Servicepacksource and sourcepath. Double click on each one and change the value to C:\ and press OK after each item.

    Get out of the registry and reboot.

    In the run box type sfc /scannow.

    My computer than ran the file checker. It took about a half hour.

    Once completed, I rebooted and got into Microsoft update.

    Because my Windows CD is a few years old and does not reflect all the updates since, I thought that there would be updates but there were none.

    For those people who do not have a Windows CD, I googled “free downloads i386 for windows xp sp3”. There appeared to be a few websites that offered the download but a couple of times my virus checker wouldn’t allow it, so be careful. I didn’t actually download any files since I already have a Windows CD but if your desperate this maybe the way to go.

  97. Leo,
    Thanks for this information. I think I have discovered a method to help with SFC recover file methods:
    First of all: SFC can run in it’s own window, so when it cannot find the file it needs: open up another explorer window and do a full system search for the exact file it is looking for. Many times SFC does not search “everywhere” for the file it needs. If you can find the file it needs,: switch focus back to the SFC window and tell it where the required file is located…SFC will continue in it’s search for the next file it can’t find and halt again..repeat the process until all it wants is satisfied. Sometimes one may even have to insert a CD or DVD that has the required file….no concern, SFC window will wait for you to find it! Kinda painfull, but it works to verify that all your system files are correct as far as SFC/WFP is concerned.
    Thanks again,

  98. Similar to a lot of the other apps MS provides, there are many glitches in running SFC, chief of which is that the updated versions of the system files do not relate to what one has on their installation CD. As a consequence of this, I have found that running SFC is virtually worthless.

    • I think you left out a step. If you type Windows Key + x, it brings up the same menu as right clicking the Start Button. From that menu, select “Command Prompt (Admin)”

  99. Thanks Glen for the tip! I’d like to know if there is a resource that would provide other tips of it’s kind, any suggestions?

  100. Dear Leo

    You state that we should have installation discs handy. I got windows 10 courtesy of a free download provided by by MS to update from Windows 8, can I still make fixes / repairs?

    Dane Hardinge

    • That should work. That’s one advantage of upgrading to Windows 10 that isn’t discussed enough. For people who didn’t get installation media with their preinstalled versions of Windows 7&8, we now have installation media.

  101. I was wondering i am not an advanced user. would I be able to Run SFC, the System File Checker.
    I don’t have command propmt I have power shell in my start up, Is that the same

    • Open Powershell. Right-click on thee Powershell icon in th Taskbar. Select “Run as administrator” from the pull-up menu. Click on Yes in the UAC prompt. Type sfc /scannow.

  102. I have used a paid software called Reimage which seems to automate the process of SFC and replaces any corrupt files with its own data base of good system files. In the course of doing it, it also does a few other cleanups like malware etc. It seems to work (at least not getting my system to an unbootable state) although I cannot tell exactly what files, if any, it has changed. The initial scan almost always says I have Windows damage. Can you do a review of this software or comment on it?

  103. I ran sfc /scannow and this is what it said:

    “Windows Resources Protection found currupt files but was unable to fix some of them. For online repairs, details are included in the CBS log file located at windir\Logs\CBS\CBS.log. For example C:\Windows\Logs\CBS\CBS.log. For offiline repairs, details are included in the log file provided by the /OFFLOGFILE flag.


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