Microsoft Outlook 2013 does NOT work with Microsoft Exchange 2003 - know this before you excitedly try to upgrade. I unknowingly fell into this trap - I tried to upgrade a client, placed the order with Microsoft Store, got the license, downloaded and installed and to my surprise after I configured outlook and launched it I realized that it did not work as my client is still running Microsoft Exchange 2003 on the backend.
Then, even more surprising the un-install of Outlook 2013 from a Windows 8 machine "hung". I had to search around and found an article that pointed to a Microsoft page that in turn provided a "fix-it" gadget that was able to successfully remove Outlook 2013. What a pain!