Wiping computer harddrive (vista)

I want to start fresh without all the junk i’ve downloaded over the past 2 years, I have my legit windows vista disc + Key, but im confussed of how to format my drive then reinstall vista,
Answer #1
You format your drive during the procedure of installing vista.
Set to boot to CD/DVD first (in bios) and boot to windows disc, and select advance options (bottom selection) during the installation and format/create parition to your hard drive and install OS.