System File Checker
By Joshua Erdman
Windows 2000 & XP comes with a very handy tool called the system file checker. The SFC tool itself will scan your computer for system files that may have been replaced when some old or poorly made program was installed. This usually happens because the programmer who made the software did not create it to check the versions of each system file it replaces.
To protect your computer from old system files, Microsoft created a special service that is built into the operating system. This service monitors your system files, and if one is replaced or deleted, ICS will automatically restore the system file.
SFC works in conjunction with a utility called Windows File Protection that keeps the system file cache: (%Systemroot%\System32\Dllcache) uppdated with the newest Microsoft Approved files as they are installed on your system. I prefer to use the system backup for the ability to roll back to a former configuration however.
To manually invoke the system file checker, be sure you have administrative access then go to the command prompt and type:
The system will immediately begin to check all the current system files and restore the cached approved copies. You may be asked to insert the Windows CD as well during the restore.
Clue: Keep in mind that after you perform a system file restore you should install the newest service pack so you are running the most current, Microsoft approved system files.
For you XP users, SFC should be used as a last resort. If you have been creating system restore points, first roll back to your latest restore point and see if that fixes your problem.
Article last reviewed: 05/22/2004