WinXP Windows File Checker

I was wondering how useful the Microsoft Windows XP Windows File Checker is, and would appreciate expert opinions from the likes of DjLizard and Tarun.

I've ran it twice on my system since December 2003, and today it did restore some original Microsoft protected system files.

WinXP Windows File Checker info and description can be seen by starting a command prompt and typing in: sfc /?