To start Quick Format! double click on its icon from the Finder.
QuickFormat! needs system 4.1 or later and requires 128K ROMS or better. (A Mac Plus or later).
You must use QuickFormat! on a hard drive. Using QuickFormat! from a floppy will not work due to the fact that floppy disks that are ejected are unmounted from the system. If you are running from floppies, you will unmount the startup disk.