Complete Wiping of a hard drive

A friend of mine got a new computer and will be giving her old one to 
another friend of hers. She wants to make sure that all her old data is 
deleted, and bought a program (it's a Win98 machine) and tried to do it 
herself. (I don't know which tool she bought.) Since she couldn't get it 
to work, she called me.

Since this machine will be starting over from scratch, wouldn't it be 
sufficient for most purposes to delete the partition(s) on the drive and 
do a fresh install, which would include formatting? I know that someone 
with sophisticated equipment could probably get old data from that drive 
even after repartitioning and formatting, but the average user probably 
wouldn't even know to look.

Am I right, or am I missing something important?

-- 
Regards,

Dick Steffens
http://home.comcast.net/~rsteff/