There is a problem when you want to install drupal with a different language than English. As you know, you should follow the link 'Learn how to install Drupal in other languages' shown in the first page during install. On the following page you find the instructions on how to accomplish this, which states:
If an alternative translation package of your choice is available, download and extract its contents to your Drupal root directory.
When in fact, drupal looks for the .po file inside profiles/$profilename/translations, not in root directory. So, returning to the first page never shows the new language.