If you have ever had issues with getting Outlook to open you will have found most them have to do with addins that are allowed but done always function.  Recently I came across an issue that would not allow the user to open Outlook not even in safe mode or after a repair of Office. It would simply start trying to open Outlook and then display a window that would say “Cannot open the Outlook window error” After trying all that I could think of I found an article from Microsoft about resetting the “navpane”.  Here is the simple step for reseting it for multiple versions of Windows.

Windows Vista and Windows 7
Start-> type; outlook.exe /resetnavpane

Windows XP
Start-> Run; outlook.exe /resetnavpane