Currently, the only uninstalled theme is Stark, and we can easily move this into the installed state by following these two steps:

1. Click on the Install and set as default link.
2. Scroll back to the top of the Appearance admin.
3. If we now look at the Installed themes section, we should see that we now have three themes installed: Stark, Bartik, and Seven. We can also tell that Stark is now our default theme by looking at the right of the theme, which will be marked as (default theme).

We can also see what the Stark theme looks like by clicking on the Back to site link in the Admin menu. We are now presented with an un-styled page, which helps to demonstrate the clean markup of Drupal.