I bought a new imac and wanted to transfer an account from an old imac. I created a new admin account and then used the migration assistant to transfer the old account. The old imac was running office 2008. We now are using office 2011. I installed office 2011 using the admin account and it seemed to work fine. When the user logged in to her account and tried to start Excel, it would just continually crash. I tried reinstalling Office 2011 as the user, but that didn’t help.
The solution was to completely remove Office 2011 and 2008. I basically followed the instructions here. Then, I reboot the system. And then I installed Office 2011 as the user and everything worked fine.