Using System File Checker (SFC) on Windows XP, Vista, and Windows 7 (32bit/64bit)

By | August 3, 2011
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System File Checker, or SFC, is one of the best features of Windows, and also one of the least used. System File Checker (SFC) is part of Windows XP, Windows Vista and Windows 7 (both 32bit and 64bit) It’s that’s too bad that more people don’t know about SFC – because it’s a really great tool. Hence we’re trying to make more people aware of it because it really is a great tool – and one you should use.

Why? Because a many common computer problems can be solved by running it; but very few people ever use it. To be honest, we forget about it too. It just so happens that this week we had a problem with one of our computers, and we happened to remember SFC and used it to repair some system files that had been replaced when we were trying an experiment. Yes, we do things like that sometimes…

Anyway, the System File Checker utility (SFC), has been available since Windows 98. The System File Checker is used to scan for missing, altered or corrupted system files and to extract the original (correct) file and replace or repair damaged files.

Probably one of the reasons why SFC isn’t more widely used is because it’s not a simple point-and-click program. It requires users to run it from DOS-like window and to enter commands and use switches. But before you decide to skip this tip right here – with the talk of DOS boxes and commands and switches – don’t skip this tip. At least 50% of you could benefit from this tip. So, hunker down, and we’ll make it as simple as possible.

There are only slight differences in these instructions for different versions of Windows. In Windows XP you can run this without opening the Command window with administrator rights, while Vista and Windows 7 users will need to open the Command window as an administrator. While you may be the only person who ever uses your computer, on Vista and Windows 7, you’re not, by default, an Administrator. Somewhere in Microsoft’s big brain, they’ve decided Windows is safer if users aren’t administrators by default. This must have occurred to them after Windows XP came out. But that’s a discussion we could have another day.

Before you start to run System File Checker, make sure you have your Windows installation disk inserted in your CD/DVD drive. If you want to repair or replace missing, altered or damaged files, that’s where Windows is going to get them. If you’re one of those who don’t have a Windows installation CD, the restore disk that came with your computer will work.

Plan on at least 45 minutes to run System File Checker. It may not take it that long, but plan on at least 45 minutes just in case. Whether or not SFC tells you to, you should reboot after you’ve run System File Checker if it has repaired or replaced any files.

OK. To run System File Checker (hereinafter known as SFC because I’m tired of typing System File Checker) do this:

Windows XP users – Press the Windows Key + the “R” key. In the Run command line type CMD and press enter.

Windows Vista and Windows 7 users: Click Start, All Programs, System Tools, Accessories, and right-click on “Command Prompt” and select “Run as administrator”. This is important. If you don’t do this, you won’t be able to do any of the following.

OK. Now that you’re all sitting there with a big black box on your screen (we hope), you need to type in some commands. DOS stuff is not very forgiving, so you have to type these commands exactly – and spaces are important too.

To run SFC so that it scans and replaces/repairs altered, missing, or damaged Windows System Files, type the following at the cursor:


(Note: there is a space between SFC and the backslash, see it? Good. Don’t forget that space!)

Here are some other commands and switches you can use with SFC:


The SFC /VERIFYONLY command scans the integrity of all protected system files but doesn’t repair or replace any damaged, missing, or altered files.


The SFC /SCANFILE command allows you to check the integrity of a single file. For instance:

SFC /SCANFILE=c:windowssystem32kernel32.dll

There are other SFC commands and switches you can use, but for us and most of you, the only command you’ll need to use is:


So there you go. Try System File Checker to check the integrity of your Windows system files. It works well and can fix some of those common, nagging Windows errors.

8 thoughts on “Using System File Checker (SFC) on Windows XP, Vista, and Windows 7 (32bit/64bit)

  1. Joan Johnston

    I had to have my OS Vista reinstalled by a repair man and since then have had problems with IE8 not being able to find certain links. An error message comes up sayig “Windows can not find ????(link url, please make sure you have spelled (the url) correctly and try it again. This happens quite frequently and different links or sites. After clicking the site or link and getting this message, I then reclick the same and the page loads. Using the above info SFC do you think it may disclose my problem or do you have any idea of what’s happening? Thanks.

    1. infoave Post author

      SFC can’t hurt, but it’s not likely to fix an IE8 problem. There’s an easier fix – try Chrome or Firefox.

  2. Raymond McCrudden

    Thank you for the SFC and all the other tit-bits you let us all know about. I’ve been with you for several years and have taken a lot of the advice and apps you have recommended – – because I KNOW they are safe.
    NOW, can you tell me if “Linux” is safe? I keep getting messages urging me to try it, but I would like to know that it is safe to do so.
    Once again, Thank you for all your hard work. Raymond

  3. Bill Jacobs, Sr.

    I do try most of your suggestions. SFC is running now – verifyonly. Thanks. Y’all rock.

  4. Bob Joynt

    I have a computer that came with windows vista installed that I legally upgraded to win 7 home. After I ran sfc I got a meesage that said my win 7 was not a valid version and it would not let me enter my product key to verify it was legitimate. I ended up having to reformat my whole system and lost a lot of data in the process. Is this going to happen again if I run sfc?

    1. infoave Post author

      SFC stands for System File Checker – it doesn’t overwrite any files that are not corrupted or missing – it has nothing to do with your Windows Registration at all. Something else must be going on with your computer, because SFC could not cause the problems you relate.

  5. Cedric Moroukian

    My Windows XP installation disk is pre-SP2. I am really worried that if I follow your SFC instructions I’m going to have to update hours of Windows updates from MS.

    Your comments will be appreciated before I go ahead.


    1. infoave Post author

      No. Running SFC is not like re-installing Windows. Nothing of the sort.


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