Cron runs Drupal background processes. For example it is used by the update module to check if there are security updates.

First install Drush:

install Drush (http://www.drush.org/resources )

Set Path

set the drush installation path in your environmental variables, so you can run drush from any directory in your terminal.
 

UNIX every 4 minutes

1. terminal "crontab -e"
2. add “0/4 * * * * drush --root=</path/to/your/drupal-site> @sites core-cron --yes“
3. save and your cron will run every 4 minutes

https://drupal.org/node/1294438

Windows every 4 minutes

1. install “Cron Script Manager” (http://cronsm.sourceforge.net/ )
2. choose “Add script”
3. scriptname “<your-drupal-site>”
4. script content: “drush --root=C:\<path\to\your\drupal-site> @sites core-cron --yes”
5. click “ok”, goto “schedule”
6. add “*/4 * * * * ?<your-drupal-site>”
7. save and your cron will run every 4 minutes

Check cron status

1. Login as Admin and goto (<drupal-site>/admin/reports/status)
2. You see the last time cron run aside “Cron maintenance tasks ”
3. There is also a link to run cron manualy.

Enjoy

You are up and running now.