Quick upgrade question

[stevedub]

Ok, my dad has an old HP pavilion with a P3 that is 535 Mhz. I just happen to have found a socket 370 motherboard at work and I would like to hook my dad up. We ordered the processor which is a 1gig P3. My one question is do I have to wipe the hard drive to install this new motherboard and cpu?

 

[turtile]

If you have XP or 2000 you will have to. ME and below won't be needed.