James wrote:

At some point I had to re-install outlook 2003 on my computer (2003 is
the only version that's ever been on this computer).

I can keep opening new instances of outlook. Before, if I tried to
open it again, it would go to my already-opened window.

What are you clicking when you think you're opening another instance of
Outlook? I suspect that if you looked in Task Manager you'd see only one
instance of OUTLOOK.EXE on the Processes tab, which means that you are not
opening multiple instances of Outlook, just multiple windows controlled by
the same instance.
--
Brian Tillman