Home »
Windows
»
Windows Programs
Summary: The System File Checker is a little known utility that validates that Windows own files are undamaged. It's a simple to run command line program.
What is the System File Checker, and how do I run it?
•
Windows XP 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 an informative message that the operating system has put the old approved version back. Not all files are under system file protection and even for those that are, there are ways around it. Occasionally system files become corrupt.
Enter the SFC, the System File Checker.
•
SFC is a good utility to run when you suspect that system files have been somehow corrupted. It validates the digital signatures of all of the Windows system files and restores any that it finds are incorrect. It will use the on-disk cache if possible, but SFC may require that you provide your original installation CD or a location with an image thereof. (See this prior article about not having an installation CD on some of the alternatives if that's the case.)
To run the system file checker press Start, Run, and then type in SFC, followed by its options.
The most common usage of SFC is this:
SFC /scannow
This causes SFC to scan your system immediately. SFC can take a few minutes to run. As I said above, have your installation CD or equivalent available in case SFC needs to replace a damaged file.
While it's not documented anywhere, if SFC replaces any system files, I'd reboot. I just like to make absolutely certain that the file replacement actually takes effect.
The Microsoft knowledgebase includes more detailed SFC documentation, including more options to check at boot time, control the size of the system file protection cache, and so on. Speaking of which, the knowledgebase also includes System File Protection documentation, covering the mechanism Windows XP uses to keep your system files safe automatically.
UPDATE: If you have no CD, but you do have an I386 directory or CD image somewhere, check out this article: How do I tell Windows where my I386 folder has moved? Once you make the changes therein, you should be able to run SFC to completion.
Article C1896 - February 28, 2004
how do i run sfc if system file is crupt
Posted by: Ritesh Gupta at July 12, 2010 11:04 AMhi, i can not open my internet explorer,what can i do?
20-Jul-2010
Posted by: sepideh at July 19, 2010 4:27 AM
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
Posted by: Nick at July 30, 2010 7:25 AMNick
how can we recover the .nk2 file
Posted by: Abdul at August 4, 2010 1:44 AMI 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?
Posted by: Kanga at August 13, 2010 7:45 AM