A. System File Checker replaces corrupt or missing protected files and refreshes corrupt or missing DLL cache components with the latest files from the installation media, service packs, or hotfix/patch locations, whichever was registered most recently. Because System File Checker overwrites existing hotfixes and patches, you have to reapply them after you run the
command. Microsoft has corrected this behavior in all Win2K Service Pack 4 (SP4) and later hotfixes and patches, which now register themselves in such a way that System File Checker can "see" them during file-restoration operations.