The profile used to install the site is stored in the variable `install_profile`. There's a few different ways you can see the value:

  - Pop into the `variables` table in your database and search for `install_profile`
  - Install the Devel module and visit `mysite.com/devel/variable`
  - Put this custom code in a template file somewhere: 

  `<?php print variable_get('install_profile', 'No install profile found.'); ?>`

Hope that helps