Thanks everybody who mailed tech advice on wiping out a second-hand PC.
Reformatting using the systems-recovery disk didn't delete original
owner's personal info.  Running f-disk from DOS prompt didn't do it.  We
couldn't load Linux RedHat without first loading WIN.  I had to hook my
other PC's hard drive up as primary drive and use that OS to totally
reformat the other PC's original hard disk.
 
Lesson learned - Windows OS & browsers have lots of security holes (why
we use Linux & web-based email instead of IE/Outlook).  You can wipe a
comp all you want but you still could leave important personal info on
it.  So be careful how you dispose of old PCs!
[Posted in FML issue 4966]