There are 3 different ways that you can install Mastodon on this machine. If you have room on your first drive, you may choose an automatic install that preserves your Microsoft Windows partition on C: (and gives you a boot menu that allows you to boot to either Windows or Mastodon), you may choose to overwrite your Windows partition and dedicate the entire disk to Mastodon. The third option is to do an interactive installation, where you have the choice of setting up your disks as you desire, and can specify which parts of Mastodon you wish to install.