You must have administrator access to use SFC.
*You need to have your copy of the Windows 2000 or XP CD handy because at some point the System File Checker will usually ask you to insert it in order to continue.
If you're using Windows XP you should first try System Restore.
Go to Repairing Windows Using System Restore for detailed instructions.
If the System Restore Point didn't work go to
Start
Run
Then type in sfc /scannow
make sure you leave one space between the sfc and the /
Or you can copy/paste the red words above.
(As soon as you type it in it should start to run. No need to hit enter.)
That will start the system file checker, it will search the system files for missing or corrupted files and replace them with cached approved copies of those files. You can watch the progress bar to gauge how long it is taking.
The cached copies are stored by the Windows File Protection utility. It caches every new Microsoft Windows approved file as it is installed on your computer in a hidden system folder called DLLCache. If SFC can't replace the missing/corrupted files with a clean cache, or it cannot find the DLLCache, it will tell you that you need to insert the Windows CD.
If you don't have a CD this article may be helpful.
Ask Leo: I don't have an installation CD for Windows XP - what if I need one?
The last step, if the System File Checker was successful, is to go to the Microsoft Update page and download the latest service pack. That's the only way to insure you have the latest approved files.
Running the SFC does take a while. It has to check every file in the system and replace the missing ones. Then you may have to insert the CD anyway. That's why I recommend going back to your last system restore point before trying the System File Checker. A restore point when you know that everything was intact.
*There are two other command prompts that you can use regarding system file checker.
These commands work in Windows 2000, but will not work in Windows XP.
sfc /cancel - this will cancel the scan.
sfc /quiet - this will tell the utility to run the scan and replace missing/corrupted files without prompting the user.
Coming up:
How to find the Windows XP files hidden on your computer if you don't have the original disc. This is handy because many PCs now come with the OS already loaded by the manufacturer.
Ways to maintain your computer using free software and built-in utilities.
Windows, Missing Files, System File Checker, System Restore, Windows XP, Woodnotwood
