you have the option to create an iso after you purchase it , and then after if you need it , you can use the ISO on a DVD or USB stick and proceed to a clean install, fallowing those step
Clean Install with Windows 8 Upgrade
if you install a start menu like "Classic Shell" the only shortcut you have to remember is this one
Windows key + C: Access the charms bar
don't spend money on start menu replacement, Classic Shell is one of the best, and it's free
Welcome to Classic Shell