I recently used the System File Checker to successfully repair a major problem with my Windows 2000 Professional workstation. I don't believe that this utility is well recognized or understood, so I'm sending this message in hopes of raising awareness of this utility as an alternative to a system rebuild. The following is what I found in Windows help:


System File Checker (sfc.exe) is a command line utility that scans and verifies the versions of all protected system files after you restart your computer. If System File Checker discovers that a protected file has been overwritten, it retrieves the correct version of the file from the %systemroot%\system32\dllcache folder, and then replaces the incorrect file.

sfc [/scannow] [/scanonce] [/scanboot] [/cancel] [/quiet] [/enable] [/purgecache] [/cachesize=x]

/scannow - Scans all protected system files immediately.
/scanonce - Scans all protected system files once.
/scanboot - Scans all protected system files every time the computer is restarted.
/cancel - Cancels all pending scans of protected system files.
/quiet - Replaces all incorrect file versions without prompting the user.
/enable - Returns Windows File Protection to default operation, prompting the user to restore protected system files when files with incorrect versions are detected.
/purgecache - Purges the Windows File Protection file cache and scans all protected system files immediately.
/cachesize=x - Sets the size, in MB, of the Windows File Protection file cache.

You must be logged on as an administrator or as a member of the Administrators group to run System File Checker.

If the %systemroot%\system32\dllcache folder becomes corrupt or unusable, use Sfc /scannow, Sfc /scanonce, or Sfc /scanboot to repair the contents of the Dllcache directory.


note: The SFC.EXE operation will/can replace important service pack files on your system, so after running this utility, it is advisable to re-apply the latest service pack. As always, make sure you have a good backup before performing any major system operation. Good Luck.

Jeffery Smith
LAN Support
July 2001