• Settings has 'Reminder Settings' - 'Allow Event Reminders', etc
• These use Reminder Email templates - though I note these use the words 'Event Notification' in the template, which I will correct
• Detail View uses 'Notify Me for the Event @' - again this needs correcting.
• Edit View has a 'Send Reminder' tick box with Time/Body/Subject options

You should not find a record entered into the Notifications table when you edit an event. Records should only be added when a user requests a Reminder from the Event Details view.

Notify/ and Reminder in the Events table are historical (i.e. before the current project team). One is the subject line, one is the body. These are populated initially from the two templates, but can be customised on the edit view per Event.

You will need the Events schedule item running for 'Reminders' to be sent. It may appear as a item with a blank name in the portal schedule if you are using some versions of DNN' Otherwise I think it has 'Notifications' in the title :-) If it is running, you should be able to check the time/date at which the reminder will be sent by looking at the date/time recorded in the Notifications record.

I'm not sure what you mean by reminders when someone has enrolled...

Cheers
Roger