Not that I can see which is why I asked in the first place. In the control panel when I go to One-Click Installs I am presented with two options:
Install new website software - Easy mode or
Install new website software - Advanced mode
There is no mention of Upgrade unless an upgrade is handled as a completely new install using the existing database, i.e., install new website software option listed.
I note it does say "Please be sure there are no files there now!" in the directory where the install is to take place, suggesting one should delete the existing files.
Is this what is considered an upgrade?