This is incorrect. All you need to do to fix the problem of the system powering down is checking that option...no need to reinstall Windows. I installed Win2K on a P2 300MHz system (it's like 5 years old), and checking that one box is all it took to make it power down completely.
FYI: I believe this thread's dead, as well as the other one you posted at that was 6 months old. Kidding aside, welcome to the forums!
<A HREF="http://www.btvillarin.com/phpBB/viewtopic.php?t=329" target="_new"><b>My System Rig</b></A> (courtesy of <A HREF="http://www.btvillarin.com" target="_new">btvillarin.com</A>)