There are a few options that I can suggest:
1) Close Outlook. Search your computer for the HIDDEN file
outcmd.dat
Rename it outcmd.old and try to open Outlook.
2) Try using the "Detect and Repair" tool on the HELP menu.
3) Try opening Outlook using the ".../Safe" switch. This will
perhaps allow you to open Outlook in Safe mode which disables
all automation that may be hanging you up. However, you still want
to identify the culprit of the hang. The article in the link below will
outline how to use the ".../Safe" switch.
OL2000: Additional Command-Line Switches:
http://support.microsoft.com/default.aspx?scid=KB;en-us;197180&