There are several places you can start. Are you running in cached mode? Try taking it off cached mode. Try starting in safe mode by closing outlook, holding down your left shift key and starting Outlook. If it starts fine in safe mode you will want to troubleshoot add-ons. If it still does not start in safe mode try remove and re-creating your profile. If that does not work you can try running a repair of Office and an uninstall/re-install if the repair does not work. Tell us what you have tried so we can help you from there. Thanks.