Galen W. Sievert, PCC, MS Ed.
wrote:

I've read a few posts about this problem: The reminder
notification box pops under or gets covered by other windows,
defeating the visual element and purpose of the reminder

Do you use Plaxo? If so, this can be a side-effect of that program.

Is there a reg hack to set the Reminder Notice to "Remain on Top"?

No.

Is there a "nag" function so that the auditory alarm continues to
sound until the reminder is dismissed? In mobile PC Outlook?

Not that I'm aware.
--
Brian Tillman