I'm trying to setup the Reminder Window to open if the Outlook tab is minimize.

Hi,

There is no build-in option in Outlook to enable this. The reminder window does not come up on top of the dialog when you are not working in Outlook, it flashes on the task bar. Microsoft's intention is to not interrupt users tasks such as typing or presenting when a reminder is triggered.

If possible, we can try to keep the sounds turned up and enable the "Play reminder sound" option (File > Options > Advanced), and then the reminder sound may get your attention.

I know that there are some third-party add-ins may achieve what you want. You can try to find out one and check if that's what you want.

Thanks,

Steve Fan
TechNet Community Support