Replace Original Operating System files without formatting

 THIS IS REALLY HELPFUL IF SOME FILES IN YOUR COMPUTER WERE CORRUPTED OR ARE ACCIDENTALLY DELETED..;.
















Microsoft has thus integrated a verification routine in Windows which can detect corrupt files and replace them with the original ones. Insert the XP setup CD and open “Start?Run”. Start the command "sfc /scannow". The Windows file protection system will verify all system files and can replace corrupt ones with the original versions if necessary.
NOTE: This procedure does not replace the system files updated through Windows Update with older versions from the setup CDs. In fact, the System File Checker uses copies of the latest files, which Windows saves in the Windows directory in the “/system32/dllcache” and “/ServicePackFiles/i386” system folders during the update