Is cron scheduled on my moodle instance?

Im wondering if my cron.php script is being called at a regular interval, as it is supposed to be.  On our other moodle server, there are scheduled tasks being called every 30 minutes that call the cron.php script. In a nutshell, the cron script does internal housekeeping - pushing out updated to activities on the site.  

Why the cron script must be called on a regular basis. Note the big bold IMPORTANT letters.

How is your cron script triggered?  Should I limit it using a password?

There are two settings in the administrator Admin |Security|Site policy - one setting to control where the cron script can be run (you can diss-allow execution from a browser - only run from command line.  Two, you can allow from a browser but require a password.  The default settings are to allow from the command line and from a browser without a password required.

The cron script does not do anything harmful, do not see why I would be concerned about it being run accidentally.  How can I tell how often my cron script has been called?  Use the moodle logs?
On our other moodle server, there are scheduled tasks running every hr (is that often enough?) - whose properties show the cron results writing to a log file like: c:\logs\moodleinstance_cron.log. The logs seem to get updated and replaced each time the cron job runs, not too helpful.

Ah, now I remember why I can't remember!

 I followed the advice of this moodle doc page and well, forgot about it.  The answer to the question then is YES, I am running cron on a regular basis on my moodle instance. I verified by checking in my downloaded installs folder I set up when setting up the server and see the file
MoodleCron-Setup.exe in the folder.

There is even a menu item on the server Start|Programs|MoodleCron

I look in the Services on the server and see the Moodle Cron service that the program mentioned above created for me.  The service has an Automatic setting, so when server reboots, it automatically restarts.  I am looking to see if I can tell the frequency which is runs, calling the moodle cron.php script. I think I specified every 15 minutes.