Formatting a hard drive along with the install of a new OS is the best option. The vast majority of operating system installations provide a "format" option as part of the installation process.
I'm working on this old iMac (350Mhz) which booted up the "Folder ?" deal. So I pop in the Norton CD to boot it up. Norton wants to format the drive. What the? Instead, I get it to check the drive ...