If you are running Windows 2000 and the operating system becomes corrupted, the easiest and least risky way to fix it is to 1) buy a new hard drive, 2) install Windows on it and then 3) set it up as the master drive (assuming it’s IDE) with your old hard drive as a slave. Then copy the data and use the old drive as a backup. The standard help-desk recommendation, always some variant of the old “you must reinstall Windows” boilerplate, puts both your valuable data and valuable time at risk. (Of course the standard recommendation should work, but then if things always worked your Windows installation wouldn’t become corrupted, would it?) The price of a hard drive nowadays seems a small price to pay to avoid hours spent in help-desk hell.