Requirements problem

OK
Web serverApache
OK
PHP5.6.24
OK
PHP register globalsDisabled
OK
PHP extensionsEnabled
OK
Database supportEnabled
OK
PHP memory limit128M
Error
File system
The directory sites/default/files does not exist. An automated attempt to create this directory failed, possibly due to a permissions problem. To proceed with the installation, either create the directory and modify its permissions manually or ensure that the installer has the permissions to create it automatically. For more information, see INSTALL.txt or the online handbook.
OK
Unicode libraryPHP Mbstring Extension
Error
Settings fileThe settings file does not exist.
The Lightning installer requires that you create a settings file as part of the installation process. Copy the ./sites/default/default.settings.php file to ./sites/default/settings.php. More details about installing Drupal are available in INSTALL.txt.
Check the error messages and proceed with the installation.