I don't know what you could have done, but I still have issues. I have a Surface Pro 128GB (please don't say that's my problem) running Windows 8 and Office 2013. It's Office 365 BTW. At one point Office was so screwed up and I was having so many issues with with the OS that I just went to a backup and restored the entire system. I can tell you I spoke to a friend that has a brand new Windows 8 laptop with Office 2013 and he is having the exact same problem.
I did not have any other Apple apps (like iTunes) on my computer. So that was not the issue. I have no idea how you were able to get this to work. But considering you did, I'm trying to figure out what makes your setup different.
I believe this is a known issue. I may have to wait for a fix from Apple, and if I do, so be it. Wish it worked for me. If there is anyone else out there with the same setup as I have and you got it to work, please let me know. Thanks.