Hi,
Do you mean that you update Office program to Office 2011, but you lost the product key? If it is, please try to follow the KB and find the product key.
http://support.microsoft.com/kb/2279109/en-us
Then, here is a forum for Office based on the Windows operation system, we are lack of the source about the Office for mac, you'd better post your question to Answers forum:
http://answers.microsoft.com/en-us/mac/forum/macoffice2011?tab=Threads
Regards,
George Zhao
TechNet Community Support
